Aquarists Online Mon, 15 Sep 2014 16:55:46 +0000 en-US hourly 1 Marine Aquarium Total Breakdown Sun, 14 Sep 2014 12:48:06 +0000

Oh no, this sounds really serious! Sounds like everything has failed, all pumps refusing to pump and the like. What a nightmare that would be. But no, the nearest thing to that would be a power failure as equipment nowadays is generally reliable.

What this is all about is the passage of time and the effects. Year in, year out all is well and the aquarist watches his/her beautiful aquarium and the changes occuring – fish grow, sadly perhaps one dies, corals change shape and even move by re-attachment. The reef becomes more like a miniature wild reef, tiny creatures scurrying about in the dark avoiding the dangers of predation. A fish only system also changes and matures, many of these systems use rocks as decor and these change colour and develop different coloured algae as the fish grow. The aquarist assists in this by maintaining the system – cleaning the viewing glasses, completing partial seawater changes, at the same time siphoning rubbish out as far as possible.

Now we get to it, it’s this rubbish that’s the problem after many years. We aquarists vary in how keen we are, some are enthusiastic and some carry out maintenance because ‘I have to’. I like the first version the most but it doesn’t really matter as long as the maintenance is properly completed. No matter how well the maintenance is done eventually a problem can arise. When the aquarist completes a partial seawater change usually the old seawater is siphoned out of the aquarium, this siphoning also removing debris which can then be discarded. Unfortunately, debris has an unhelpful tendency to gather in inaccessible places such as under and behind rocks and corners. Helpful though the siphon is there isn’t a way of reaching these hidden accumulations.

Well, that’s not true, there is. Eventually the debris has to be removed by dismantling the aquarium. Just thinking about that could cause an aquarist with a beautiful aquarium to tear his hair out! Remove all those rocks, sand, corals, fish and anything else kept. The stress on the aquarist and the livestock is high. But if the dirt is clearly excessive, and it is easy to know when it is, a clean up must be done. First, discipline – do it. Pick a time and day to do it when there isn’t going to be interruptions. Ensure there are enough containers in which to place rocks, sand, seawater and creatures. Mix plenty of new seawater to act as a top-up supply, none will be wasted as any excess can be used towards a later partial seawater change . Cloths need to be available to cover the floor area. A couple of beers could be standing by too! Take a photograph of the aquarium through the viewing glasses, if possible from both sides and the front, this should assist in re-construction.

There will be some damage to the view but it should be minimal. Grit those teeth! Ensure heaters are not exposed to air. Siphon some seawater into the container that is to hold rocks. Now take the top visible rocks out and place them carefully in the container. If it’s a reef aquarium there will be corals so these must be carefully placed to keep the corals on top. Now take the lower rocks out and place them on the rocks already there avoiding any corals – use a separate container if necessary. This puts them in the correct order – bottom and top – for putting them back.

Siphon out as much of the remaining seawater as possible, avoiding dirt. Running the seawater through a filter cloth could help. Ensure seawater goes into the container that will hold livestock. The seawater being saved will be going back into the aquarium. Leave a few inches of seawater in the aquarium for the fish and any other livestock.

It is a good idea to use two nets to minimise the time spent chasing fish around which causes more stress to the fish never mind the aquarist. When they are caught gently put them in a container. Siphon out all remaining seawater as far as possible avoiding dirt. Ensure the seawater in the livestock container does not cool excessively – use a heater if necessary.

Now the clean-up can commence. Remove the accumulated dirt completely and dispose of it. Work quickly but ensure that dirt, including that on the glasses not normally seen, is removed. Now things are progressing. No beer yet though. Thoroughly clean any sand that is in use. This can take some time. The use of tap water for this is acceptable, the sand can be flushed in a bucket until it is clean, just keep tipping out the tap water after each stir with the sand still in the bucket. Note: cleaning sand does not include any DSB (deep sand bed). Let the sand drain so that as much tap water is removed as possible.

Everything clean? Right, into reverse then. Return the lower rocks first trying to place them where they came from. This will not be completely accurate of course. When the lower rocks are in and stable, the upper rocks can go in. The tops of the upper rocks are evident by the different colour as they are exposed to the light and of course they could have a coral attached. To assist use the photographs if they were taken. Ensure the rocks are stable. Now place any sand required into the aquarium.

Return the seawater from the rock container to the aquarium, ensuring that any dirt is not returned. Return the seawater from any additional container that was used. Check the level and top-up from the new mix as necessary. Turn on the aquarium heaters and other equipment once the seawater is at the required level, but leave the lights off. Again using two nets if needed, catch the fish plus any other livestock and gently return them to the aquarium. Do not expose shrimps and similar to the air. There isn’t a requirement for the livestock to be acclimatised as they are essentially in the same seawater. Take this opportunity to check the rock structure once more, ensure it is stable. Leave the lights off until the following day, this will help the livestock to de-stress. In the same way, do not attempt to feed them. Let them have some quiet.

Put away all the bits and pieces and clean-up the area if needed. Now the aquarist can de-stress. Have a beer, you’ve done well! The aquarium scene will repair quite quickly as damage to the rocks and that on them should be minimal. Mother Nature will re-assert herself.

There is one advance on the system that can be made at a major clean-up time as described above. It’s also achievable when a new aquarium is being set up. This advance will delay the ‘total breakdown’ requirement considerably and is recommended. For more information go to the March 2011 Archives from the Home Page and click on the title ‘Keep It Clean’. I have this in my reef aquarium which has been running for 13 years, there is about 2 inches width of sloping debris at each end of the aquarium under the rocks and the rest is clean. No need for a breakdown, at least not for a considerable while.

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Why Not Have A Hermit Crab? Sun, 10 Aug 2014 15:18:33 +0000


The marine aquarium, be it fish only or reef, can be fascinating and beautiful. The reef aquarium is the one that attracts most aquarists and understandably so. Colourful corals sitting on rocks with various fish swimming about and maybe other lifeforms. Why not a hermit crab? They are different and interesting, sometimes amusing with their antics.

The aquarist needs to have some experience before considering a hermit crab. There’s a problem – how is ‘experience’ measured? Generally the aquarium must be fully matured not new and ready for stocking or not long after stocking, in other words reasonably ‘aged’, preferably six months at least. Seawater parameters, meaning temperature, pH, SG, ammonia and nitrite (the last two should never appear) need to be totally acceptable without high nitrates, the last indicates that overfeeding doesn’t take place. As an unscientific comment, the seawater needs to be very clean.

If the hermit crab develops a sickness it cannot be treated with copper. This is not a problem as they are already in a reef environment with no copper corals in the same way fish are.

Hermit crabs like a rocky environment with crevices and caves so the reef system is ideal. The fish that are in the system should be peaceful and small, not unusual for a reef system.

Though hermit crabs are not usually difficult to keep, they are a little delicate. This does not mean that they are fussy eaters or likely to be easily damaged, but they do suffer from a less than ideal environment. Therefore after being taken from the sea and transported they can often be below par and need a good environment and feeding to strengthen again.

When the crab is obtained from the store it should be transported home without delay. The bag should be hung in the aquarium to allow the temperature to equalise and a small amount of seawater discarded from the bag say every 10 minutes and replaced by aquarium seawater. Once this procedure has gone on for about an hour it should be safe to release the crab into the aquarium. Keep the bag and crab underwater and gently tip the crab out into a quiet corner as far as possible. Leave it alone and after a while the legs will appear and it will go off and probably hide though not all do, some start exploring immediately.

Feed the fish as usual and don’t worry if the crab doesn’t get any, wait for it to settle down, usually this doesn’t take long.

Hermit crabs get larger and need to adopt a bigger shell from time to time, so it’s necessary to ensure there are one or two sensibly larger shells lying about. The crab will inspect them and if interested change. The shells should be natural and not man-made ie plastic. From time to time the crab will get rid of its exoskeleton and this should be left in the aquarium as the crab could well eat it.

Feeding a hermit crab is not difficult as they aren’t fussy. Usually they’ll happily eat any algae available and also small algae pellets, just the one or maybe two. Fish food will also be consumed if any escapes the fish. To ensure they have enough, place some food – a bit of fish or shrimp – near them and see if it is eaten. It will soon be known how much the crab will eat in the same way as it is with fish.

So a hermit crab like other inhabitants of a reef system demands a quality environment. It also need some spare shells in case it needs to move to a new one because of growth. Also adequate feeding without overfeeding which again is the same as fish.

So next time there’s a visit to the fish store look for a hermit crab just for interest. If a purchase is considered find out the size it will eventually grow to. Also get a couple of shells for it to move into should it wish.

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Special Lights On A Reef Aquarium – Why? Sun, 20 Jul 2014 09:49:17 +0000

“The fish are fine under standard non-aquarium lights, even if I buy just white lights they are still ok. Why not corals?”

This is an understandable question. Marine reef fish come from the same areas as the corals so why spend more? There is a good answer and no, it isn’t just a good way of making money!

First let’s make a comment about ‘just white lights’. This can mean any kind of bulb. Marine fish will live happily under ‘just white lights’ as they need to see and basically that’s it. However, lights designated for marine aquarium use (for fish only this is usually fluorescent) should not encourage unwanted algae. Lights that have an unwanted spectrum particularly in the red area can. So two tubes, one marine blue and one marine white will be better. Two tubes allow for a ‘dawn/dusk’ sequence (using two timers, see below) and with some fish the light output enhances the fish colours.

So what about corals? With fish it can be an advantage to use blue and white as above. With corals it is essential. Why? Within the flesh of light loving corals are small single celled algae called zooxanthellae. These cells are very tiny, a square millimetre could hold about 10,000! They live as tenants, the rent is nourishment for the corals. The zooxanthellae can supply between 60 and 150% of the coral’s energy requirement*.

How do the zooxanthellae obtain the nourishment for the corals? In the same way as living plants, including visible algae do – from the sun. This is known as photosynthesis. Corals having ‘tenants’ possibly started because tropical reef waters are nutrient poor.

Now we need to go a little further. We’ve mentioned marine white and blue as needed colours, this is because light is lost in seawater and different colours are lost at different depths. Some corals live near the surface, others live deeper down. High penetration of seawater is achieved by blue light and it is known that zooxanthellae are able to make good use of this light. The blue light gives a lovely colour to the aquarium picture on its own, but the light is balanced by the white light. Also, as with fish only, the aquarist can create a ‘dawn/dusk’ sequence. The sudden application or withdrawal of light isn’t good, so the blue lights can come on say 15 minutes before the white (dawn) and reverse at the end of the day (dusk). The overall message is, for success with corals the lighting should be correct.

There are choices as usual and technology advances all the time. However, in my view simplicity isn’t a bad thing and so ‘straightforward’ lighting is required.


First, there are fluorescents which are readily available and suitable. Ready made lighting canopies can be obtained containing more than one fluorescent but let’s keep costs down and buy single tubes. Check the length of the aquarium and make sure the ones we choose will fit. Consider reflectors for the tubes and obtain the maximum that, put in lengthwise, will fit across the aquarium. The number of reflectors dictates the number of tubes of course. Obtain marine blue and marine white tubes, if the reflector number is even make one half blue and one half white. If the number is odd make the extra one white. Now it is easy to get the correct power units – these can be obtained so that two tubes run off one so creating more simplicity. Two electric timers are needed for the ‘dawn/dusk’ sequence. The supplied power connectors for the end of the tubes are specially designed so are safe if the reflectors/tubes sit on the glass cross bars (but does not remove the need for caution when electricity is close to seawater!). The usual tubes used are called T5’s. Fluorescent lighting is reasonably cheap to run and does not emit excessive heat. The tubes need to be changed at the latest once a year, probably better at 6 to 9 months.

So that’s simple and not a tremendous expense. However (oh yes, here it comes!) tubes cannot be used on any reef – it depends on the depth. The light has to reach the corals with sufficient power so research and/or advice is needed. There’s plenty of information available, including on this site.


Another popular lighting system is called metal halide. These come in prepared packages though DIY is available. Dependant on the length of the aquarium, one or more light units are hung above, often one for every 3 feet, not too close to avoid them being splashed (this is because the bulbs become very hot). The light unit(s) are connected to controllers which could have timers. The bulbs available are designed for marine use and come in various light types some being more white and others more blueish in appearance. Some aquarists make use of one or two marine blue fluorescent tubes as well, so the zooxanthellae are happy and a ‘dawn/dusk’ sequence can be achieved. The metal halide system is a very good lighting system for deep reef aquariums as light penetration is very good. Different power level bulbs are available, two being 250W (watts) and 400W. Reading those wattages gives a clue to the downsides, the first being they are expensive to run, more so the more bulbs there are. The second downside is the heat the bulbs emit which can quite easily heat up the seawater. This additional heat could be a real problem in summer when natural heat is higher as the seawater temperature increases – the heater(s) fitted will of course switch off but the temperature could continue to increase, even to the point where aquarium life is stressed or threatened. To resolve this problem could mean the purchase of more equipment, a cooler. So again research and/or advice is required. With the lights on between 8 to 12 hours a day electricity costs are going to be very noticeable, plus the possibility of additional problems as mentioned. The bulbs too will need replacing at generally the same periods as fluorescent lights.


Finally, there is now what appears to be an excellent choice of lighting. This is the LED system. Basically blue and white LED bulbs are mixed to give good coverage of the aquarium. The lights can be a DIY project, or purchased as an array that covers a large area of the aquarium surface. Alternatively, LED strips can be obtained, these are similar to fluorescent tubes and reflectors in size and are fitted in the same way though the blue and white is present in each strip. Though things are improving all the time the disadvantage of these systems is the high cost, particularly the ready built full array. The strips are not as bad though several are required. There are some definite advantages though. The first is the very long expected life of the LED bulbs which could be up to 20 years! The second is the low running costs – obviously they still need electricity but nothing near the demands of a metal halide system. The third is the heat output, it isn’t going to be a problem and will not normally affect the seawater. In some systems there is an in-built fan unit that directs any heat generated away from the aquarium. Another ‘advantage’, and this depends on how the aquarist views it, is the ability for example to simulate clouds passing over the reef. Most aquarists would probably view this as a non-essential high level luxury and fair enough. It is available in or with some full canopy arrays and will add to the already high purchase cost.


So special lighting on a reef aquarium is essential. It is of course up to the aquarist to decide which type, the decision will effect the later costs of running the system and the cost of buying it in the first place.

One thing is for sure. If the reef system is to be a success, if the aquarium is going to be as beautiful and interesting as it has the potential to be whatever its size, and if the aquarist is to meet the ongoing cost of running the system, the correct choices have to be made. So research and advice, then consideration. It’s worth it!

(*Reference: Eric H. Borneman. “Corals”)


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Have A Successful Marine Aquarium, Don’t Skimp Sun, 29 Jun 2014 14:35:42 +0000

We more experienced aquarists tend to go on a bit about starting a new marine aquarium. This isn’t because we’re showing off our knowledge though there’s no doubt a bit of that arises occasionally, it’s because we’ve done things in the past that new aquarists often do – that is we’ve done things wrongly when setting up the system.

Having seen a marine aquarium, often a reef system, at the local dealers or wherever many state how beautiful they are and move on. Others state how great it would be to have one meaning the first step has been taken. Following this could be a look on the internet or a visit to the local fish store.

The next move, having looked at the available space and obtained any partner’s agreement, is to go and have a look at marine aquariums more closely. More often than not this means a trip to the local dealers. No problem so far.

The first aquariums to be considered are often ready built systems and this often delivers the first surprise – the cost. Most likely the first ready built system looked at is a big one and well equipped. If it can’t be afforded then downsize or consider the ‘put it together yourself’ variety. If one big or smaller can be afforded then the potential aquarist should go home and make price comparisons using the internet. If the local price is not acceptable then talk to the dealer. There are reasons why buying from a local shop is good, but there is a need to ensure the price is reasonable. If all is acceptable then it is really a good idea to consider a self built system too. Ask the dealer to quote a price for this for a same size system. If the ready built system still appeals, no problem. But wait.

Why wait? Find out what demand the system will have for electricity, then a cost per day, week, month and year can be calculated. Also, how many gallons does the system hold? There will be a cost for sea salt for the initial fill (though not accurate take 10% off the gross gallonage, this is close enough for a very rough net gallonage estimate) and also an ongoing cost for weekly seawater changes, the amount of the new weekly seawater, initially anyway is 10% of the net gallonage.

If everything is still acceptable, then there is a requirement to consider the cost and type of stocking. Under no circumstances should a marine system be overstocked. A decision is required – is it to be a fish only or reef system. Fish only can contain more fish subject to size, a reef less fish to help ensure seawater quality remains high. Take advice, look on the internet, consider, don’t just go ahead. If a reef is chosen, ensure that the lighting supplied with the ready built system is suitable for corals.

At this point another decision is required and again advice and consideration is needed. Biological filtration is required, without it or if it is inadequate there will be disaster! ‘Living rock’ in sufficient quantity and quality is the modern best way of biological filtration and in addition is wonderful for creating a reef (or rock formations if fish only). Unfortunately the rock is expensive. Another method of biological filtration is a correctly sized canister filter containing suitable materials. The big downside of the canister filter is that they do not remove all the ‘baddies’, one is left which is not particularly dangerous in itself but can lead to severe problems if unchecked (nitrate). Overloading the filtration by for example introducing fish too quickly can produce disaster, poisons can accumulate which will kill the livestock (ammonia, nitrite).

What about setting up a system by purchasing seperate components? Nothing wrong with that and cost savings can be achieved. Needed is an aquarium (surprise!), a suitable support for it (an aquarium full of seawater and rocks is very heavy!), biological filtration as above, a heater (or better two at half the wattage each), a thermometer so that the seawater temperature is monitored, a protein skimmer of suitable size for the net gallonage and lights suitable for the type of system being constructed. Also a control device is required for the lights as they will not be on all the time. Powerheads (water pumps) will be required to move the seawater and create flow – usually at least two are needed, it depends on the size of the aquarium if more are required. When the price for all of these is obtained if it is acceptable then fine. If not, downsize the aquarium or don’t proceed at all.

Anyone considering constructing their own system from seperately purchased components, if the cost is acceptable, should proceed as with a ready constructed system above.

There are four other very important bits to obtain and must not be missing on a new system. These are test kits for ammonia, nitrite and nitrate and also an hydrometer (the latter is used to check the ‘saltiness’ of the seawater, called the specific gravity).

There is one piece of equipment that is not usually listed as definitely required. This is the reverse osmosis (RO) filter. This filters tap water very thoroughly removing toxics that are detrimental – a good one will produce 90/95% pure water which is used to mix with the sea salt. It is a worthwhile addition as unwanted substances are not required in a marine aquarium. These filters are not hugely expensive and are recommended particularly as much of tap water destined for safe human use has unwanted content.

If the cost is found to be a little excessive on any aquarium component don’t be tempted to reduce the size of anything which is deemed correctly sized! Wait until the correct equipment can be afforded. It’s worth waiting or the cost further down the line, sooner or later, could be high.

The procedures mentioned are not meant to be the ‘a to z’ of setting up a marine aquarium, far from it, but a path to initially follow during the usually confusing early period. In truth, keeping a marine aquarium is straight forward provided all is well in the first place.

There are three words that cover the requirement for success and these are research, discipline and patience. Success is in the hands of the new aquarist. If the system equipment that is being used is fully adequate, if the stocking has been carried out correctly and if ongoing maintenance is adequate all should be well. There isn’t a cast- iron guarantee of success where Mother Nature’s creatures are involved but the aquarist can move the indicator for success very high up the scale.

So, exercise discipline and patience, wait as long as necessary, use adequate equipment and stock very carefully. Lots of information is available in books and on the internet and a knowlegeable local dealer should also give good advice as it is in his interest to do so. That successful marine aquarium is waiting to come to life.

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The Aquarium Shop Can Advise Everything? Wed, 21 May 2014 16:59:49 +0000

Any potential marine aquarist could easily consider that the best source for advice when a marine aquarium is being considered is the dealer. This is completely understandable – who do we ask when there’s a problem with the car or TV or we want advice on a new kitchen?

This young couple went into a pet store and saw some fish and thought ‘what beautiful creatures’. They approached the assistant who advised them the common names of the fish and the couple bought two and took them home looking very pleased with themselves. A couple of days later they were back at the store and advised that the two fish they had bought had died but the other fish in the aquarium were perfectly fine. When asked they advised that the dead fish hadn’t displayed any sign of disease.

The shop assistant was quite puzzled and asked what type the other fish the couple kept were. The couple advised they were goldfish. ‘But the fish you bought need warm salt water’ the couple were told. ‘Oh’!’ they said.

It cannot be verified but the above short tale is supposed to be true. Assuming it is who was at fault, was it the couple or the assistant? At the end of the day it was the couple, if they had asked to buy the fish the assistant could quite reasonably have assumed they knew what they were doing. The final responsibility is with the home aquarium owner.

Marine aquarium shops are generally reasonable (but not overall), with some considerably better then others. To give good advice they need good information. A good experienced dealer will ask questions and advise ‘when’, ‘what if’ etc.

I used to use a local very small shop (sadly marine aquariums are no longer dealt with). The dealer realised very quickly that I knew considerably more than he did. To his credit he used this to his advantage, asking questions when I went in for a coffee and even occasionally referring other customers to me if I happened to be in the store. This doesn’t indicate I’m anything special but shows that he was doing his best for customers.

From time to time I use a much bigger, though not huge store about 40 miles away. I travel this distance because it’s worth it.

Going in to the store is a bit off-putting, there’s a quite narrow drive down the side of a house and a very small car park at the back. The building housing the store looks quite scruffy. However, inside it is well-ordered, the aquariums are clean and reasonably laid out. There are no struggling or dead creatures. They actually sell to the trade but are happy to serve the public too (just have to avoid the despatch day for the trade!). I wander around at my leisure and when I’ve identified what I want the assistant comes over. The price is confirmed and, if the purchase is for fish, they are held individually and carefully by net at the front of the tank for inspection. If I’m satisfied they are quickly bagged. Technicalities could be discussed and it’s obvious that the assistants have experience and are reasonably bothered about the welfare of the livestock. The shop also quarantines the fish stock and do not keep the salt water in the for sale aquariums dosed with copper.

The above is the type of shop that is gold to a marine aquarist – helpful, knowledgeable and to be trusted. However, as mentioned they can advise only on the information they receive, if they receive poor information it’s the aquarist’s fault and the aquarium life could suffer for it.

No matter how good a marine aquarium shop is, at the end of the day they need to sell as selling means survival.

The new marine aquarist needs to know what type of aquarium is wanted, the space for it and the basic equipment required. Equipment prices can be checked on the internet for comparison purposes. The internet and/or books can supply lots of basic information. Once the information is held and covers the basics then try the local dealers and try and judge their abilities with beginners. They need to keep it simple and realise that we’re not all millionaires but that marine livestock need correct technical support. Information could be given by the dealer but hardware purchases made from somewhere else, the internet for example. It’s always worth a try – tell them the price an item can be obtained for and from where. They might just drop the price to obtain a sale.

Even if for example not all hardware is obtained from the dealers they’ll be happy if some livestock and ongoing requirements are because they are selling as they need to. The new aquarist will be happy because the dealer will get to know them and their aquarium.

Who knows, maybe a friendship will grow. ‘See you next week for coffee!’

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A Spare Heater, It Just Sits There…. Mon, 21 Apr 2014 16:15:39 +0000

There’s quite a list of equipment to purchase when a marine aquarium is being set up and keeping a marine aquarium can’t be called the cheapest hobby on earth.

However beginning aquarists usually follow the guidelines carefully, ensuring the size of this and the capacity of that is adequate. After all, buying a cheap or undersized item is not going to save money in the long or even the medium term. An adequate replacement could be required so economies at the beginning require caution.

Equipment nowadays is generally very reliable though there is always the chance of failure and so it is with a heater. Most marine aquariums run on one heater which includes a built in thermostat. The recommendation is for two, each heater being one half, or close to one half the amount of the required wattage. Two are recommended as if one fails then hopefully the aquarist will notice the problem before serious consequences arise. The heater(s) have a built in thermostat which is normally set at between 75 and 80 deg F (if there are two heaters they have the same setting).

There are variations of course. On my system there are two thermostat controlled heaters which are connected to an exterior thermostat. The exterior controlling thermostat detects the seawater temperature through a sensor and reacts to changes by applying more or less heat. The thermostat continuously pulses power through the other two immersed heaters increasing or decreasing the length of the pulse as required. In this way the seawater temperature is kept very steady. The exterior thermostat is set to 77 deg F. The two submersed heaters have their thermostats set at 80deg F. Therefore if the external thermostat stuck in the ‘on’ position the seawater temperature would rise to 80 and turn off protecting the livestock. If the thermostat totally failed… it would have to be noticed!

So, this external thermostat sat there for over eight years with the indicator light pulse always very regular. As with other equipment, a visual check was made from time to time, no problem, the electronics are brilliant! It becomes normal, ‘nothing wrong’.

But, one day, the temperature had risen for no obvious reason. This was noticed on the internal thermometer on the viewing glass. It was immediately assumed that some external influence was at work, after all the indicator light was still happily blinking on and off.

The seawater temperature however continued to rise so the adjustment knob was moved to zero. Still the external thermostat was not suspected. At zero the light stopped blinking as it should. It was turned on again and the temperature set to normal. After a while, the temperature was clearly slowly rising. Still not understanding, a reliable mercury thermometer was placed in the seawater to check the internal one which could have failed. Same result, rising temperature.

At this point the exterior thermostat did become suspect. The adjustment knob was moved to normal and the indicator blinked as usual. The knob was moved to a lower setting and the length of the pulses increased! The sensor was clean and undamaged. At last it was clear the external thermostat was at fault.

Lying in a closet was a heater/stat which had never been used, pretty obvious looking at some dust and the still coiled wire. The thermostat had been set at 77 deg F. It was a very simple matter to unplug the exterior thermostat, hang the back-up heater in the corner of the aquarium and plug it in. The temperature was monitored more regularly than normal but all was ok.

Has this put me off external electronic thermostats? No. The unit lasted as said over eight years in continuous use. It didn’t cost that much and I now have a replacement of the same type and make.

As the temperature was rising why didn’t I leave it to cut off at 80? I’ve had my fish and corals a long time (the fish with me the longest is a flame angel (Centropyge loriculus), eleven years. The corals mainly are longer than that). I didn’t want to expose them to any potential stress at all even though 80 is not usually a lethal level. Thank goodness the temperature didn’t go unnoticed if it was falling.

So there we are, a piece of equipment that for most of the time had been superfluous to requirements. I was so pleased that I had it.

When the overall cost of setting up a marine aquarium is considered adding a back-up heater isn’t so bad. Then of course there’s the lives of the livestock.



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Using Cover Glasses On A Marine Aquarium Fri, 28 Mar 2014 12:51:49 +0000


Some ready built aquarium systems are sold complete with cover glasses fitted, often of the sliding type. There could be two or three, perhaps more on a large aquarium. A standard aquarium would need them added. However, when considering a marine system are cover glasses actually required?

They do have their advantages. The first one and hopefully one that wouldn’t normally be required is that the casual flick of cigarette ash or whatever by say an inconsiderate partygoer would not enter the seawater. This would also apply to accidental additions to the seawater even by a careful aquarist, though perhaps unlikely. Protection against these kinds of events could be desirable to some, but are not really essential because the events are unlikely.

Ok, then what of the aquarium inhabitants themselves? Fish for example, some are known to be ‘jumpers’. A cover glass would protect from the danger of a fish leaving the seawater permanently. However, the aquarist could provide a covering net which would serve the same purpose. Also overall the potential for fish jumping is low.

Are there any other reasons for or against cover glasses? Of course there are, there can be a debate about just about anything!

Having cover glasses fitted means consideration of safety from the start, particularly with ones cut and fitted by the aquarist as opposed to the already supplied versions which should already be as safe as possible. The glasses should not fit so tightly that they only just fit, they should be reasonably loose so that removing and placing them is easy. This is helped by gluing with silicone a small handle at the front middle of each glass to give assistance with lifting. A handle can easily be made from two small lengths of rigid plastic glued together at right angles and then glued to the glass. It is also important to ensure that sharp edges round the glass are blunted, this is easily done with emery paper or a sharpening stone which will slightly round the edge.

The major advantage of using cover glasses is the reduction of evaporation. All aquarists know that seawater evaporates (the water content that is, not the salt) and there is a requirement to maintain the level. This is done either manually or with a top up device. If cover glasses are in place then the amount of water required to top up will be much reduced, meaning the required reservoir for topping up will be smaller. Evaporation reduction is the advantage to consider, about the only major advantage.

What of the disadvantages then, there’s obviously going to be some. The first one that comes to mind is that the cover glasses supply another item to routinely clean. They sit above the seawater fairly close to it and are subject to splashes and condensation. With a reef system it is essential to deliver the maximum light and correct spectrum to the corals so the glasses must be clean. After the aquarium night period the glasses are often covered in condensation but this clears after a short period of lights on. Nevertheless there is a slow accumulation of fine debris and/or marking. Cover glasses could also interfere with the dissipation of heat, which is not a good idea when warmer months are with us. Aquarists who use a surface fan to assist cooling would need to remove the cover glasses to increase effectiveness.

Cover glasses and reef systems being mentioned I did an experiment many years ago. I doubt if the experiment would be considered scientific, but at least it was an aquarist checking carefully. For a measured six months I ran my soft coral reef system with cover glasses on (they were properly cleaned throughout the period of course). Then I removed them and after a further six months considered any changes. Apart from the expected increase in evaporation there weren’t any or none that I could see or measure. The corals seemed unaffected one way or the other though soft corals are generally easier than the hard types. This maybe doesn’t suggest anything to anyone but I found it interesting nontheless. The lights in use were fluorescents.

So if there wasn’t any difference in the experiment, why didn’t I put the cover glasses back? Simply because I read an article by a respected marine aquarist and scientist that cover glasses could interfere with the ‘breathing’ of the aquarium. The seawater surface  acts as a large air/water interface where oxygen exchange takes place (provided there is sufficient seawater movement). Cover glasses could impair it. Also, to my untrained mind anyway, cover glasses must have some effect on the light passing through either on intensity or spectrum. Finally – maybe I’m lazy, I don’t have to clean them!

There is another advantage cover glasses provide which should be mentioned. When the aquarist goes on holiday the aquarium is either left to automatics or a family member/friend kindly agrees to feed as needed and also do the top ups. With cover glasses evaporation is greatly reduced as already stated, this makes it easier for the kind person helping out and the required reservoir of top up water is also reduced. If an auto top up is in use then again less water is required in the reservoir and/or it is less likely to run out.

So when I’m at home to tend my aquarium cover glasses are not in use. I’ve kept them though for when I’m not here.

Most of the reef aquariums I’ve seen are open topped and that seems the way to go. Fish only systems could have cover glasses if the aquarist is willing to accept the additional cleaning.




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Marine Aquarium Lighting Is Really Important Mon, 17 Feb 2014 10:50:48 +0000

A well set up and stocked mature marine aquarium is beautiful, even to those who are not interested in having one. Anyone passing by one of these aquariums, be it private or public, will stop and gaze.

Setting up a marine aquarium takes time and patience but when done it is well worth it. A lot of attention is paid to the equipment and quite rightly so. The livestock depend on the correct choices so that the habitat is suitable and healthy. Lighting has long been used in the home and commercially to enhance for different effects. Spotlights are an obvious example, another is colour designed to attract attention or maximise the feeling of comfort. Colour is also used in the marine aquarium but in this case it has to be more specific particularly in a reef system. On the natural reef many corals and other lifeforms are collected from between 15 and 30 feet (not precisely of course!). Because of this depth they have become, over a very long time, accustomed to the light in this area. At the surface of the sea all the colours of sunlight are present. The sea absorbs light as it passes down into greater depth. The first to disappear are red, orange, yellow, indigo and violet. The deeper into the sea the more blue it becomes. At the levels mentioned  the ‘red end’ of light has gone and therefore corals have evolved to make use of that remaining, particularly blue. This is not an overall rule as there are lifeforms that are close to the surface and can make use of other colours, but for the marine aquarist blue is important.

Why should blue be important? Within the flesh of most corals kept by aquarists are tiny algae cells, millions in a single coral. These algae cells, called zooxanthellae, help the coral to feed and dispose of waste. They are very important to the coral and if something goes wrong and the coral ejects them, called bleaching, there is trouble. We’ve heard of coral bleaching on the wild reefs, a cause for concern. So the lighting that we provide is very important. (There are more causes for coral bleaching than lighting problems.)

Lighting types can be identified by means of the Kelvin scale, simply shown as a K after a number. For example, at the seawater surface natural sunlight is rated as 5,500K, the number representing a very warm white light. 20,000K represents a cold looking blue light and represents deep water areas.

With a fish only system the lighting is not of such great importance as there aren’t any corals present. The fish need to see and the aquarist needs to see the fish, that’s just about it. However, if warm white tubes were to be used there is a danger that unwelcome algae could be encouraged so this is not a good idea. It is suggested that two tubes are used with reflectors, one white and one blue as described for a reef system. This will also enhance some fish colours as a bonus.

The reef system is more demanding with light. Again, it is suggested that two colours are used, one being white and the other blue. As many tubes as can be fitted with reflectors should be used. The whites and blues should be in equal numbers and fitted alternately, or if it is an odd number the extra should be a white. It can’t be any white or any blue though, we need to have specific light output. With fluorescent tubes these should be what is commonly called ‘marine white’, that is tubes that are 10,000K or close. The blue tubes are again commonly called ‘marine blue’ and are often sold quoting ‘400 -480nm’ (nanometers) and could also state that the output peaks at 420nm. Why? This is because the range and peak quoted represent the area required in particular by the corals for their tenants, the zooxanthellae.

This all sounds rather technical but for the aquarist it isn’t a problem. Fluorescent tubes are often sold declaring their intended use hence ‘marine white’ and ‘marine blue’. There isn’t a requirement to put on a white coat and look scientific. The manufacturers have designed their lights for specific use and are usually easy to select.

The blue tubes have another advantage and this is that they could make some corals look wonderful because they fluoresce. This is caused by the UV output from the tube impacting the coral and is not a problem. The photo at the beginning shows my aquarium with all fluorescent lights on. The photo above shows the aquarium with blue lights only. The following photo shows the lighting array, three whites and two blues. The aquarium is 24″ deep and contains soft corals.

There are of course lighting systems other than fluorescent tubes. Though more expensive the LED array is the most modern concept. Used a lot on reef systems but possibly declining by now because of running costs is the metal halide system. These mentioned systems have not been covered here as it is more advanced and fluorescent tubes are perfectly suitable for ‘standard’ aquarists. Remember though to have regard to the depth of the aquarium, that is the depth the light needs to penetrate.

Having white and blue lights has the advantage that the aquarist can arrange a ‘dawn/dusk’ sequence using electric timers. It is bad practice to plunge the aquarium into darkness or instantly expose it to bright light. Have the blue lights come on first (dawn) and 15 minutes later the white lights. At the end of the day have the white lights go off first and 15 minutes later the blue lights. Though not matching the natural events it works well. The lights should run between 8 to 12 hours a day. Try 10 hours, then reduce or increase by half an hour over an extended period if wanted (nothing should be rushed).

As time passes there is a requirement to change fluorescent tubes. This is because as they age the light output reduces and the spectrum can shift. If tubes are not changed then there could eventually be a detrimental impact on the zooxanthellae and therefore the health of the corals. The manufacturer should suggest the frequency of renewal. Fluorescents should be changed no later than one year old, I change mine every nine months. My soft coral reef has been running for over 10 years now with the same type of lighting system and has flourished. The fluorescent tubes are T8’s, not the later T5’s. Sometimes the corals are a bit too vigorous and this leads to some ‘fragging’ (pruning of corals where the cut off pieces are grown into new corals). In the first two photos a cut can be seen on the bottom left large coral.

The number one on the list of importance for a marine aquarium, fish only or reef, is seawater quality. With a reef system, a very close second is lighting. Pay attention to both and the aquarium should be truly beautiful.

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So You’re In Charge, Yes? Tue, 14 Jan 2014 18:26:52 +0000


No this isn’t about domestic arrangements! This is about marine aquariums and the persons they belong to.

We, the aquarists decided on having a tropical marine aquarium. We spent a long time deciding on a lot of things, ‘what size should it be?’ and ‘where will it go?’ are examples. Following there are all those decisions about equipment such as filtration, heaters, skimmers, pumps, lighting, thermometer, test kits and others. By the time all this was satisfactorily completed perhaps there was some surprise that the fish and maybe corals stage had actually been reached. All the care that had to be taken in selection of the livestock should be really worthwhile.

So we are in charge, sounds pretty like it to me. But if we stop to think for a little while, most of the decisions we made are based on the needs of the livestock. Seawater salinity and temperature levels are what they require. Habitat, as far as we’re able, is what they require. So yes, we are making the decisions on what to have but to a large extent those decisions are being dictated to us. So who or what is doing the dictating?

Fish and corals have evolved over a very long time and their requirements are pretty clear. Most corals require the correct lighting, corals and fish require clean seawater in a defined temperature range. There should be an approximation of dusk to night and dawn to day using electric timers. Seawater movement needs to be adequate for the disposal of waste and adequate oxygenation. There needs to be minimised stress which means there needs to be hiding places for fish to enter, acknowledging their in-built instincts. Food needs to be available of the correct type. So it goes on.

Ok, we do all of that so we’re in charge, stop going on, it’s obvious isn’t it? Yes it is. We put the system together, we run the aquarium, we feed the livestock, we maintain the environment by means of test kits and partial seawater changes. The aquarist is in charge.

However, is not the aquarist also an employee? No, not to the livestock though sometimes it could seem that way. We are an employee to a very powerful another, ignore her demands at your peril. Yes, some heads might be nodding in agreement, the boss has to be female! She’s Mother Nature.

If we can keep our aquariums within Mother Nature’s limits then all will be well. The limits are what she defines for our fish and corals. If those limits change, for example seawater quality changes in a particular way, Mother Nature could take advantage and give you a lovely garden of green algae. If a beautiful fish is mistakenly introduced and it grows too large the problems this causes will be clear.

So day to day aquarists are in charge, from the beginning to the end of the aquarium’s life. We should remember however that we are dictated to by another, and as long as we keep Mother Nature happy we should be too.


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Testing Or Testing Patience? Fri, 13 Dec 2013 18:31:47 +0000


Testing is an important part of the marine aquarists routine and includes the obvious one, seawater condition tests. Included though not quite the testing as generally understood is checking powerhead performance and the like.

It took quite a while getting the aquarium up and running. Fish only or reef, patience at times was a test itself as the routines of what and which were completed. Eventually of course all was done and there, a lovely marine system.

The aquarist has to feed the fish of course and this is never missed as it is obviously a necessity and fortunately also a pleasure. This happens daily, though the odd miss is not a problem.

As time passes there is another potential problem. The routine of testing the seawater becomes more of a chore. This is not to say that interest in the aquarium has diminished, simply that doing tests over and over week after week could become boring as nothing ever changes. The basic tests are of course to do with seawater and cover ammonia, nitrite and nitrate plus specific gravity (sg). So the aquarist decides to decrease the frequency of the tests and do them fortnightly. This in fact is fair enough as long as there has not been any negative variation in the test results. Testing is to prove the condition of the seawater and if the tests are positive it is safe after a few months to test less frequently. However at the first sign of quality reduction testing should be increased until all is proved to be quality stable again. A question needs to be asked as well – why has a reduction in quality occurred? The appearance of increased nitrate for example could indicate excess feeding.

It is the same with routine seawater changes, the need to carry these out is essential but the frequency is not written in stone. The changes are required to ‘freshen’ the seawater and at least partially replace lost trace elements etc. The minimum suggested amount of seawater to change each week is 10% of the net gallonage (including any sump). The amount of seawater changed can be varied upwards if for example there is a problem with nitrate. If the seawater tests as mentioned previously are fine then routine changes could be made every two weeks. A further reduction in changes is not recommended. Change frequency is also based on the organic load of the aquarium – the number of fish being the obvious example – more fish, more food, more waste, more seawater quality reduction.

Testing is not confined to special liquids and test tubes. ‘Tests’ include such things as observing the fish when feeding them ensuring there aren’t any abnormalities to be seen, checking the outflow of power heads (very easily done), checking the protein skimmer is properly functioning (again very easily done) and the like. Don’t forget the lights – are they getting a layer of salt on them, if so wipe it off with a damp rag (but beware of bulb heat), a salt layer on the bulbs could reduce the amount of light getting where it’s needed. Do the lights require changing? Fluorescent tubes and metal halide bulbs have a finite life before the output power and light freqency begin to change. Poor lighting will not do corals much good.

So testing doesn’t need to test patience as well. The aquarist should carry out frequent testing when the aquarium is new, however as above if all is well there isn’t anything wrong with a little adjustment in testing practices. Adjustments should never be extreme and the aquarist of course should never put ‘I can’t be bothered’ first!

We aquarists much of the time think we’re in charge. Well we are to a considerable extent, we put the aquarium together, we introduced the livestock and we decide what the fish get to eat and how often. The truth is, however that we are in fact supporting the one really in charge, Mother Nature. For example, fish have evolved over a very long time and require appropriate food, some even specialized food and failure to provide it will bring reduced health or worse. If we slacken our observations of the aquarium environment too much and seawater quality reduces then Mother Nature could take the opportunity to introduce more life. How about some of that green stringy algae that grows everywhere? Maybe another type could appear to vary the scene a bit, a carpet of reddish brown algae covering rocks and sand. Getting rid of these could really test patience. No aquarist wants that.

As experience increases routine testing and seawater changes can be varied on a reasonable basis without mishap. Applying patience is part of this routine. For the most part this produces a happy aquarist and that’s what we all want!


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