Automation And The Marine Aquarium

There are jobs that can take up time with a marine aquarium whether the system is fish only, corals only or mixed reef. Some of these jobs cannot be automated, such as cleaning the algae off the viewing glasses. However there are some straightforward basic  tasks that could be.

Light is essential on all  systems though the type of light (the spectrum) is particularly important on corals only and mixed reefs. Light itself is important on all aquarium types as it provides the rhythm of life – when it goes dark fish find their hide holes and corals could start to close. At the same time night life could appear such as the tiny creatures in the rocks and sand. Light is the first item to automate – most aquarists do but there are those few who turn it on and off manually which is not recommended. First there needs to be a set pattern or rhythm to ‘on’ and ‘off’ periods, livestock need this in the same way that  humans do. The lighting ‘on’ period needs to the same day after day, with corals this is set to the length of time the corals need. All that is needed are electric timers, usually two. Why two? It’s very bad practice to plunge a dark aquarium into bright light or vice versa as this is very unnatural and causes some livestock panic. Fish for example need time to settle and go to their night time abodes where they have security. Daytime doesn’t start with instantaneous sun-up but there is a gradual increase of light. Coral only and mixed reef systems usually (but not always) employ strong white lighting and also blue (actinic) light as the latter is very useful to corals. So if the white light is turned on by one timer the blue can be turned on by another. The blue comes on around 30 minutes before the white and turns off about 30 minutes after. Though not a proper dawn and dusk this is sufficient for the ‘night time is coming’ and ‘wake up now’ needs of livestock. A fish only system could have say two white tubes fitted – it’s simple to fit one additional blue tube which enhances the fish colours as well.

Another job that could be automated is seawater level. Maintaining the correct level is important as this has an impact on salinity. It has to be said that topping up manually each day isn’t usually negative as far as salinity is concerned as the amount of water lost through evaporation in one day shouldn’t have a large impact, nevertheless there is an impact. If an accurate graph were to be drawn of salinity levels over say a week, the up/down fluctuation would be smaller with automated top up than with manual as the automated system applies several smaller top-ups in a day. Though it’s probably correct to assume that most marine aquarists (except perhaps those with fish only systems) run their aquariums open that is without cover glasses, those that have cover glasses will lose less water. If the water top-up is to be automated all that is required is a simple system that can be purchased commercially and which are not particularly expensive. These mostly consist of a float valve (to signal when water is required and when water is at the correct level), a small electric pump (to send replacement water when needed) and a water reservoir. Once set up the aquarist need only ensure the system continues to operate correctly and also keep an adequate supply of fresh water in the reservoir. This supply should really be RO (reverse osmosis) water.

There is an important point that should be made about water in the reservoir and this is it must be fresh water not salt water. When water evaporates from the display aquarium it is fresh – the salt is left behind. Using salt water will mean a slowly increasing salinity level. Salt could be lost but this is usually from salt creep, this is when salt encrustation is seen on wires, glass etc. that are close to the seawater surface.

The final basic automation that could be considered by the aquarist is feeding. Experiments have been done where several feeds a day have been injected into the aquarium so that fish can feed more naturally (as opposed to one or two major feeds each day). There have been successes with a few of these efforts but the system is troublesome. The major problem is keeping the food fresh (the foods used are a mixture of ‘meaty’ substances in small bits plus a little very small flake mixed in). The food is in a reservoir which is stirred continuously to keep the food dispersed so it can be successfully pumped to the aquarium and the pump used for this is a very small specialist pump (called a peristaltic pump) that is able to deliver small programmed doses (on the same principle as medical ones that are used to deliver small precise amounts at given times to patients). These are the first problems, stirring the mixture and ensuring the pump isn’t going to block as the tubes used are narrow. The major problem as already said is keeping the food fresh – these foods can ‘go off’ quite quickly. This was overcome by refrigeration – the food to be used was kept in a very small refrigerator from which it was pumped on demand, usually the pump was not inside with the food but a narrow tube (which is the method of delivery with these pumps) came through the casing.

Any aquarist who is not into general experimentation (which includes most of us) can easily see that the effort and expense is not worth the result. Provided an adequate diet is fed and overfeeding is avoided, feeding once or twice a day doesn’t seem to do any harm to most livestock types, though as always there are exceptions such as small mouthed specialist feeders who often  can’t compete with bolder greedier types. These more timid types are dealt with on an individual basis by the aquarist.

What about other automatic feeders then? These are available commercially and as mechanisms are generally reliable and not overly expensive. They usually clip to the aquarium side near and above the seawater surface. This positioning could be a problem, the fixing needs to be secure. The devices have several partitions so that one meal or more can be delivered per day at pre-set times. Unfortunately, for the devices to deliver the food it must be dry so it doesn’t clog or stick which rules out some marine foods such as frozen and leaves the choice as flake. Flake is placed in the device as desired and is delivered according to the set programme to the seawater surface. The flake has obviously not been pre-soaked so it floats on the surface for a while anyway. It could be that eagle eyed fish will see it and come to the surface to eat. The problem is that some perhaps most of this floating food could disappear over a weir to a sump or down a surface feeding filter intake and the like. These devices are not desirable in another way – they take away the enjoyment of interaction between the aquarist and the livestock. Most importantly, they could remove or reduce the time when the aquarist watches the fish and notes anything that could be a problem.

There are other more advanced devices that could be automated but above are the basic ones which most aquarists could consider. The one for lighting is considered essential. The one for water top-ups is for the aquarist to decide, many find it easy to top up each day though circumstances and aquarium size vary. The one for feeding is easy to consider – the first refrigerated method is more than most aquarists need or are willing to cope with. The second simpler flake feeder devices could be useful, but if to be considered it’s suggested that one is seen in action first on a friend’s system. If impressive enough then consideration needs to be given to security of delivery which depends on individual systems – the food needs to get to the fish and not be gathered up in a sump or filter.

There Is A Bad Reading But The System Should Be Mature

Relating to marine aquariums what is meant by ‘mature’? It means that the aquarium system is ready to support life. In fact there are two levels of maturity: the first is the initial level which is achieved after the system has been set up and the biological filter (some call it life support) has been activated. The second is when the system is truly mature, this is when the livestock is present in entirety and the biological filter has fully settled down to the task it faces, this could take many months. The first level could take many days to weeks.

The two main biological filter systems in use are live rock and canisters, the first being the most desirable. The biological filter is populated by bacteria. The bacteria deal with the toxics which, without them, would appear in seawater tests, these being ammonia and nitrite. Ammonia is produced by fish etc as a natural part of life and the bacteria convert ammonia to nitrite and then nitrite to nitrate (depending on the type of filter). In an enclosed system ammonia and nitrite are dangerous and should measure on tests as zero.

It is necessary initially to look at both types of filter separately so let’s start with the canister filter.

The canister filter is an electric pump positioned on a cylinder so that seawater can be moved from the display aquarium through the canister and back to the aquarium. It’s generally best to have the seawater intake at one end of the aquarium and the outlet at the other end, with the returning seawater exiting at the surface (this is to aid with re-oxygenation). As the seawater goes through the canister the bacteria that live on the media carry out the conversion of toxics. When the canister is first set up there aren’t any bacteria present of course. It’s necessary for the aquarist to carefully choose an adequately sized canister then obtain bacteria friendly media (some are better than others) in sufficient quantity. The bacteria have to be introduced to the media and this is best done by the use of commercially available maturation fluid which includes full instructions for use. The procedures are simple and involve regular testing for ammonia and nitrite. The filter is considered mature when readings are zero, indicating that the bacteria are doing their job.

Note that canister filters do not deal with nitrate (because of the presence of oxygen). Some types of media have claimed to be able to deal with nitrate but this ability is usually short lived. To avoid putting undesirable nitrate into the aquarium from the start before livestock are present, put intake/exit tubes into a bucket containing seawater at the required temperature. When tests indicate zero for ammonia and nitrite the filter is ready to support livestock in the display aquarium. The seawater in the bucket should be thrown away. It isn’t necessary to have the filter attached to the aquarium initially: the bacteria are being introduced to the filter media not the aquarium. In the future as the aquarium slowly matures to the second level bacteria could appear elsewhere but it’s the canister media that’s the main home for the hard working bacteria.

Live rock is probably the most used filtration. Not only does it provide the bacteria media, it ‘seascapes’ the aquarium as well. There aren’t any trailing wires or tubes to be seen. All that is required is for the aquarist to purchase sufficient ‘clean’ rock and introduce it to the aquarium making sure that there is good circulation around and, as far as possible, between the rocks. ‘Clean’ (or ‘matured’) rock is that which has been kept for a period by the retailer so that organisms that are dying or dead can be cleared away. These organisms are there because live rock comes from the sea and some of them cannot withstand the stress of transportation. If dying or dead organisms were left they could be a source of ammonia. In addition, there could be undesirable organisms that hopefully will be spotted and removed. If the aquarist is lucky some desirable organisms could survive.

Live rock is able to deal with ammonia, nitrite and in addition, within reason, nitrate (‘within reason’ means there’s a limit). This is because the bacteria require oxygen, those on the surface get it easily and convert ammonia and nitrite but those within the porous rock don’t but still require oxygen – to get it they remove oxygen from nitrate thus breaking the nitrate down.

Ok, so the aquariums set up and there’s a troublesome reading of ammonia or nitrite that shouldn’t be there.

 First of all, with the canister, is the aquarist using that all important requirement patience? The time required for a canister to initially mature varies and the need is to wait until it does. Don’t overdose the maturation fluid thinking that the process will speed up, it won’t. Follow the instructions carefully and stop dosing when indicated, often when the test turns red. What is happening is that the bacteria are building their numbers so that they are able to deal with the toxics present. If the filter media is ok and the pump operating correctly, the bad reading will go, often disappearing in a very short period, sometimes in not many hours. The sequence of readings is usually ammonia, then nitrite, then these clear. Nitrate often appears as the cycle progresses.

If the tests showed zero readings but a bad reading has returned, presumably this is during stocking. Stocking the aquarium starts when the initial maturation point has been reached. Stocking, particularly with fish, much less so with corals (corals present a lower biological load) should be done slowly. After the introduction of two small fish or even just one (in a 50 gallon aquarium) there should be at least a two week period before further fish are introduced, and then just two more, or one if it is larger. The reason is the biological filter has to adapt to the increasing load – if organisms are introduced too quickly the bacteria can’t cope and an undesirable test result is likely. Stop stocking and wait for any bad reading to go keeping an eye on fish already present. If they show signs of discomfort, carry out a partial seawater change. Testing should continue very regularly during the whole stocking period.

If a bad reading appears after full stocking is reached or is being approached and even after waiting it doesn’t disappear, check the canister filter. Is the electric pump working (is seawater coming out of the exit pipe?) They are generally reliable nowadays. Are the inlet and exit tubes properly attached? Is there a blockage preventing correct seawater flow? If no problem is found and the bad reading persists, check the capacity of the canister – manufacturers usually indicate the gallons the canister can deal with. If the canister can’t cope, mature a bigger one (mature the additional media and when ready transfer the media from the smaller canister). Perhaps there is room for more media in the smaller canister. Obtaining the correct size canister is clearly best done at the planning stage.

During maintenance, the bio-media within a canister filter can be cleaned if necessary to maintain seawater flow and general efficiency. The cleaning should be done in warm seawater (the old seawater after a routine change for example). Stir very gently. Never clean in tap water or there will be bad readings on testing!

The aquarist who uses live rock should adhere to the stocking principle outlined above. Some beginning aquarists believe that when live rock is introduced then stocking can go ahead as the rock is fully ready. This is incorrect and could be the reason why a bad reading has appeared.

Live rock is already populated by bacteria, but the adequacy of this population varies. First there are different types of live rock and the amount needed of a particular type should always be checked. Second the rock has to be cleaned as indicated above and in this period the rock lays quietly in seawater without livestock. Therefore there isn’t any ammonia being generated to support the bacteria’s needs and the population could reduce. To counter this, dead organisms could be producing ammonia and it is possible, for a time anyway, that the bacterial count could increase. The clean rock then goes into sale tanks where often it lays without livestock. Again the bacteria population could be decreasing. If the rock lays in a sale tank for a long period the bacteria count could be seriously depleted. It is always worthwhile checking how long since the rock was cleaned. Even with this knowledge the adequacy of the filtration ability of the rock will be unknown, hence the slow stocking.

If a bad reading appears during stocking then stocking any further should be postponed until the reading is correct – in other words until the bacteria can handle the bio-load. If the stocking is nearly complete or fully so and a bad reading appears and does not correct, then it is possible that there is a seawater circulation problem. If a check of the circulation pumps shows no problem then it is probable that the amount of rock is insufficient for the bio-load. Rock as desired should be purchased and introduced and a close watch on seawater test readings maintained. Always ensure that there is adequate seawater circulation when the new rock is introduced and of course that it is stable.

The maximum stocking level relevant to the net gallonage of the display aquarium should never be exceeded.

Generally, with canister and live rock filtration, it’s more likely to meet a problem with a fish only system than a reef one, all things being equal. Why is this? Fish present a higher bio-load to the bacteria than say corals. In a fish only system there are usually many fish for the size of aquarium, and they are all of course fed regularly. In a reef system, as said, the corals present a much lower bio-load and if there are fish present they are often smaller and should be less in number.

It’s not likely that serious problems will appear in a new aquarium system provided the aquarist prepares the system for the bio-load it will contain, that is fish only, a mixed reef system, or corals only. The new aquarist should always display patience, harder to do than might be thought. In a complete system a sudden problem is unlikely if maintenance is properly applied as anything untoward will become apparent in good time, particularly as the aquarist will have gained experience and understand the system thoroughly.

Beautiful Encrusting Algae But There’s A Small Downside

Marine aquarists try very hard to create a beautiful aquarium – whether the system is fish only or reef that is the target. These attempts are generally successful and often the picture is enhanced by Mother Nature. Mother Nature obviously provides the ‘eye targets’, the colourful fish and corals.

In the aquarium are usually rocks – whether fish only or reef this could be to provide homes and also be decorative. Both, particularly reef, could be ‘living rock’ for biological filtration. This rock is normally interesting in shape and over time provides a base for algae growth.

At this point the assumption is that the aquarist has properly maintained seawater quality which in turn means that stocking levels are acceptable. It’s also assumed that lighting is adequate.

Encrusting algae, often known as coralline algae which is more accurate, is lovely. It can cover upper surfaces of rocks and make a real contribution to the overall aquarium picture. Often it is introduced to the aquarium on live rock from the dealer or another aquarist. Helpfully, ordinary maintenance seems to assist in its spread.

I’ve taken some photos from areas in my aquarium (I’m not an expert on photography so hopefully they’re adequate!). The heading photo has nothing to do with the subject, it’s just that my flame angel (Centropyge loriculus) cruised by and I couldn’t resist pressing the button.

The next two photos show interesting formations created by the algae as it grows. As is often the case there is beauty in the detail. There is much more in the aquarium that isn’t shown.

Ok, so what’s this downside that has been mentioned? There’s always a price to be paid for anything, and the price demanded for this algae is in an extension of maintenance. However, this isn’t much.

The algae not only uses rocks as a base, it’s quite happy to use glass. On the rear glass this doesn’t matter, and in my case the left hand glass can be left as well. However, the other viewing glasses need to be cleaned periodically. Of course this is already done to deal with the green stuff that accumulates but unfortunately a magnet cleaner doesn’t usually remove the encrusting algae. Therefore a razor cleaner is the best tool.

The next two photos show growth on a corner and on a horizontal glass pump support. Coralline algae seems to like growing in the corners of the aquarium – or at least it does in mine. Cleaning is not a problem with a razor but make sure the razor is sharp and also have regard to the silicone joints if there are any.

Calcium testing is normally carried out where there is a known need for it. There is another test that is generally beneficial particularly with a reef and that is alkalinity. I maintain my alkalinity at about 4.0 meq/l (it drops off slowly, I test at routine seawater changes) and this seems to benefit the encrusting algae – not only the coralline but other types present as well. Maintaining a higher alkalinity is considered to be desirable with a reef system but is not essential.

It has been mentioned that routine maintenance could assist with the spread of coralline algae. When the algae is being scraped off the glass it disperses into the seawater and this seems to generate further growth in other areas of the aquarium, though I have never seen any scientific or other confirmation of this.

One more concern has been raised in the past – does the coralline algae presence on live rock reduce the effectiveness of live rock filtration. Bacteria essential to the well-being of the livestock dwell within the rock so could seawater fail to reach the bacteria causing their demise followed by serious problems? ‘No’ has to be the answer. Though, as far as I know, there hasn’t been serious or scientific testing of this question there hasn’t been a reported failure of filtration, again as far as I know. There are marine aquarists far and wide who are delighted with the presence of the algae. Personally I’m also delighted and have never had a problem with filtration because of the algae presence.

---

Enough Light? Must Be

Watching a marine aquarium is a great pleasure and probably one of the major reasons why so many keep them. With a reef system sometimes a new arrival is seen to appear, or a species of coral that is already present appears somewhere else.

On a few occasions I’ve noticed arrivals that must have come in with coral rock, such as a very dark and tiny crab that was very timid and only appeared at ‘dusk’. Its presence was shown by an exploratory claw appearing out of a crevice. The crab hasn’t been seen for a long time and no doubt has gone.

Corals too can appear when new live or coral rock is introduced. In this case the coral type is already present in the aquarium with a fairly large colony, and the new appearance is in a completely separate part of the aquarium.

As far as I can tell, the main colony is a Rhodactis species (the purchase was made years ago and the dealer didn’t have a clue). Rhodactis are also commonly known as hairy mushrooms and mushroom anemones. I think it could possibly be Rhodactis indosinensis – but is this correct as most grow larger than my specimens? Maybe they are Discosoma species. The colony is receiving plenty of light as it is half way up the reef (about half way up the aquarium depth). The new one, however, is not; it is right down at the bottom. The aquarium is 24″ deep (21.5″ from lights to coral). Further, this new growth is at the end of the aquarium and is partly shadowed by another coral.

Is my lighting system powerful? No is the answer, it’s a fluorescent array of five tubes, three marine whites and two marine blues (actinic). They’re not even T5’s, they’re T8’s. The reef is furnished with soft corals and they are perfectly happy but I had to wonder at the growth of this new one. The blues will penetrate well but even so….

The original colony is in an ideal spot apart from seawater flow which is a bit too vigorous, they prefer weak flow. However, I’ve left things as they are as the mushrooms are clearly healthy and open well, though not to as large an extent as with lower seawater flow.

The new one is the reverse; it’s in an area of slow flow. However, as said, I wondered about the light. It has been slowly growing for about 8 months now and has reached a size of 3″ across, which, because of the slow seawater flow, is full expansion. However, though I believed the slow growth must be because of light, or at least the lack of it, it seems this could be wrong. Looking at one of the references available to me * it seems that though light is no doubt an influencing factor it isn’t that important, as strong lighting is not required by Rhodactis species though they will tolerate it. Discosoma species prefer in many cases reduced light.

How did the new growth appear? It is possible it’s by natural detachment, but in this case is more likely to be my error. From time to time I have to get out the trusty and sharp scissors and reduce the colony to prevent interference with other species. Part of this is catching the detached parts. These corals are easy to ‘frag’ so if a small part escaped my attention and lodged it is more than likely to grow.

So there we are – what started as a general belief followed up by some simple research has turned my notion upside down. Goes to show how important basic research is. As far as identifying the species, I’d need a marine biologist and I bet there’d be uncertainty even then.

(*Reference: Aquarium Corals. Eric H. Borneman)

---

Making Live Rock

The major bio-filtration media in use by marine aquarists, whether they keep a reef or fish only system, is probably live rock and for good reason.

Premium live rock is rock that has been fairly recently harvested from around the reefs, meaning it is ‘rubble’ rather than hewed from the reef itself. This rock has growths of all sorts which could be of interest to the aquarist. Unfortunately, live rock needs to be cured after import which simply means that all the dead and dying organisms on and in the rock have to be removed, meaning that pollution will not occur in the aquarium. However, for the most part there are tougher organisms that do survive and they could make an appearance in the aquarium, this appearance could be months after the rock has been introduced. Live rock can also harbor unwelcome organisms, such as the aquarium weed aiptasia, an anemone that could become a real nuisance without controlling attention.

In addition to natural organism introductions with the rock, it is very decorative. Reef and fish only aquarists are able to construct a very interesting and decorative structure which suits livestock very well.

The next great attribute of live rock is mentioned in the first paragraph – bio-filtration. Living organisms in the aquarium will literally be poisoned unless there is some means of negating the toxic substances that they produce. The two major toxins are ammonia and nitrite, and a much less dangerous one is nitrate. Dwelling on and in the live rock are oxygen requiring bacteria which convert the toxin ammonia to the toxin nitrite, which is then converted to nitrate. Bacteria living within the rock also require oxygen but find it hard to obtain, therefore they extract it from the nitrate which breaks the nitrate down releasing the residue from the aquarium as gas. The process from ammonia to gas release is known as the nitrogen cycle.

Live rock is a great commodity for the aquarist, providing the major and essential job of bio-filtration and also doubling up as decoration. The rock must of course be present in sufficient quantity to deal with the bio-load present, which is created mainly by fish.

There’s only one problem and that is cost, it’s expensive, particularly the premium grade. It’s expensive to air freight rock. This cost could be controlled up to a point by using base rock as the lower part of the rock structure and premium grade for the surface – but it is still expensive.

One way of avoiding this cost is to create live rock, which isn’t difficult. What is required is inert porous rock, that is, rock that is known to be free of any substance that could be harmful in seawater and also porous. This type of rock is often available in local fish shops and at a very much lower cost than the live variety. It isn’t any use purchasing solid non-porous rock. The second requirement is that there needs to be as much rock as would be used if the live variety were bought, which should ensure that the amount of bio-filtration media will be adequate.

If necessary the rock is thoroughly rinsed before it is placed in the aquarium to form a structure as required. The aquarium is then filled with seawater (note the net gallonage for future use) at the required specific gravity (SG) and heated to the design temperature. Seawater circulation should also be turned on. At this stage there isn’t any need for lighting. The seawater should be left to settle down to the required parameters. Check the seawater SG once it has heated up as temperature could affect it.

Once the seawater is at the required SG and temperature attention can be given to processing the rock. Anyone who has ever used a canister filter for bio-filtration will be aware of the process. A commercial maturation fluid is obtained and added to the seawater at the amounts given in the instructions. Test kits for ammonia and nitrite are also required, and the seawater should be tested in accordance with the instructions. Eventually the ammonia reading will disappear, followed by the nitrite reading. Once the aquarist is sure the reading remains at zero for both, the rock can be considered to be initially mature, that is, there is an initial population of bacteria to deal with toxins.

A test should now be done for nitrate; a level will probably be clearly seen. This nitrate should be reduced by a seawater change until it is as low as possible or preferably undetectable.

Slow stocking can now commence, turning the lighting system on of course. It is important that ammonia and nitrite tests continue, if there is any indication of either ammonia or nitrite stocking should cease until the reading(s) are zero again and remain so. The bacteria need to adapt to the increasing bio-load and must be allowed the time to do so.

Eventually of course the aquarium will be stocked as required. The bacteria population is able to stabilize and after a further say three months can be considered as fully mature. Routine seawater changes, as with any system, need to continue as does testing.

Wait a minute though; we’re supposed to be creating live rock which should be able within reason to deal with nitrate. So it will, in time. It takes longer for the nitrate reducing bacteria population to establish, and once it has the nitrate should be controlled. Relative to live rock and nitrate what does ‘within reason’ mean? It simply means that if the aquarium is often overfed and the toxin reducing bacteria produce a lot of nitrate, and the aquarist is missing routine seawater changes, the nitrate could be too high for the bacteria to control.

Ok, so now we have an aquarium filtered by live rock. What about the natural growths that could occur (though not always) with natural live rock? These will obviously be absent as the rock was initially dead. With both the fish only and reef system, if the environment is of high quality it shouldn’t be long before encrusting algae’s make an appearance. In a fish only system it could be necessary to seed with a small piece of rock from a friend’s aquarium that already has encrusting algae on it. In a reef system, when the aquarist introduces corals they will usually be attached to pieces of natural rock. These rocks should contain organisms that should seed the other rocks provided a high quality environment is maintained. Before long the previously dead rocks should look completely different – just like natural live rock.

So for a considerably reduced price live rock is achievable. What the aquarist needs to provide is some patience (required by all marine aquarists) and considerably less money. There is great concern about the future of the wild reefs and concern has been expressed about the impact of live rock collection, so the aquarist who produces his/her own will be assisting with reef protection.

---

Remember The Lighting

What is the most important part of a marine system? Lighting? Well no, it isn’t, seawater quality is the number one with both fish only and reef aquariums.

High seawater quality means there shouldn’t be any indication of ammonia or nitrite. Nitrate should be as low as possible (the guideline for a reef system is less than 10 ppm (parts per million) and for a fish only less than 30 ppm. Phosphate should preferably be undetectable. pH should be stable in the region 8.1 to 8.4. SG (specific gravity) for a fish only should be stable within the range 1.022 to 1.025, and in a reef system 1.024 to 1.025 (there are variations with SG which more advanced aquarists use for specific purposes). With a reef system there are more seawater parameters that could be monitored but those given are the basic ones.

So what has seawater quality got to do with lighting, this text is about lighting according to the title.

There are occasions when an aquarist is completely at a loss to explain why the corals are not as they were, with reduced growth and less expansion. Tests have been carried out on the seawater and it is top notch. What could be the problem? Perhaps a disease that is hard to spot? In fact it could be the lighting. Great care is taken when setting up a reef system to ensure the lighting is suitable and the corals, hard or soft, will confirm this.

With a fish only aquarium the lighting is not of such great importance. Its function is to permit the fish to see and the aquarist to see the fish. In addition, if the lighting, which is usually fluorescent tubes, is chosen with care the fish colours can be enhanced. Some colours react really well to ‘marine white’ tubes, and likewise to blue (actinic) ones. There isn’t any reason why more than two tubes cannot be used, but at least two should be in use, say one ‘marine white’ and one blue (actinic). Doing this not only assists with fish colouration, it permits the aquarist to create a ‘dawn/dusk’ sequence. Using electric timers, the blue tube comes on first, then half an hour later the white. At the end of the day the white goes off followed by the blue. This avoids washing the aquarium with sudden light and plunging it into instant darkness, both bad practices.

The reef aquarium is a different story. With these systems lighting is a close second to seawater quality. Most of the corals commonly kept have zooxanthellae in their flesh. Zooxanthellae are single celled algae and the coral gets its colour from them. In addition the corals obtain food as ‘rent’ from the algae; authorities have quoted the level of food supply as 80% or more. Algae, as other plants, require light in order to photosynthesize. The light needs to have sufficient power to penetrate the seawater to the depth of the corals and reach the algae. Power is measured in watts (W). If power is insufficient then the algae will get too little, this is why different power requirements are quoted for aquariums with different depths. In addition, the spectrum needs to be suitable. Light is measured in Kelvin, otherwise known as the colour temperature. Though there is more than one colour suitable for photosynthesis with some corals, blue is the one commonly used by aquarists. Blue penetrates deeply into the seas and oceans. Generally all light types use the Kelvin scale. If metal halide lighting is in use, the bulb(s) commonly used are 10000K and 14000K. The higher the number, the more cold or blue the light appears. Many aquarists use blue (actinic) fluorescent tubes alongside their metal halides. Many commercially produced metal halide arrays incorporate these tubes.

With reef lighting it is also advantageous to have a ‘dawn/dusk’ sequence. Whether the main white lights are fluorescent or metal halide, having blue tubes allows the sequence to be arranged.

So corals, or rather the zooxanthellae in their flesh, need lights that have a suitable colour and in addition the lights need to have enough power to penetrate the seawater.

Provided the aquarist has chosen the correct lighting system in the first place and other requirements are as they should be, the reef display should be lovely. This continues for longer than a year or more when eventually the aquarist notes that the corals aren’t as they were, as said earlier. There appears to be a slow reduction in extension. Perhaps there is a slight and maybe continuing change in colour. Again as said, the aquarist gets out his/her array of test kits but nothing appears wrong, the seawater is still of high quality. How about the lights?

With a fish only system there doesn’t need to be too much concern about the lights. As said they are normally fluorescent tubes and need changing when there is clear discolouration or blackening at the end of the tubes. It is not long after this point has been reached that the tubes are likely to start flickering or fail.

With a reef system the lighting needs more careful monitoring. To the aquarist’s eye there seems to have been no change to the light, as the tubes and/or bulbs switch on normally and they seem just as bright. This is not so however. As time passes the tubes and/or bulbs start to reduce in power which means that, given time, less light will reach the zooxanthellae. In addition, over time the spectrum shifts slowly and the painstakingly chosen lights emit a changed colour, again something the corals will not appreciate.

The best way that a reef aquarist can proceed is to keep a notebook; it only needs to be a small one. In it can go all sorts of memory joggers – including when the lights were first turned on. The manufacturers usually suggest in their documentation how long the lights should maintain their original specifications. There is considerable discussion within the hobby about light reduction/change periods, some suggesting that lights should be changed every three months. I have no facts or scientific reports to argue with, but I feel that period is definitely safe but rather short. Changing the lights no later than one year seems to be a reasonable general guideline. My reef is lit by a fluorescent array, and I change every nine months and have not had any problems.

The aquarist carries out many maintenance activities, a number of which are quite rightly concerned with seawater. There are the test kits that need to come out of the cupboard regularly, the routine seawater changes that partially replace lost trace elements and dilute the sometimes troublesome nitrate. Then there’s cleaning that very useful device the protein skimmer and ensuring that seawater flow is optimal. Plus the rest.

The lights are just there. They may get an occasional wipe with a damp rag but that’s usually all. They’re very dependable and all that is needed is a bulb/tube change after a specific time lapse. This will keep the corals happy if other parameters are good.

Happy corals mean a happy aquarist.

---

Interesting Maybe, But It Doesn’t Matter

Interesting?

O3        +  NO2 ………> O2         + NO3
(Ozone + Nitrite ………> Oxygen + Nitrate)

Could be, but in the majority of cases the answer is no.

A potential marine aquarist or even an existing one keeping a reef or fish only system is likely to shy away from anything approaching scientific, and fair enough. (The above is straightforward and understandable if the symbols are understood but gives the general idea). Being a marine aquarist doesn’t mean a white laboratory coat is required or a ‘professor’ appearance, though there are one or two aquarists who love to mystify the marine aquarium and elevate their accomplishments. There isn’t any need to boost success with an aquarium; it is there for all to see.

Some books contain explanatory formulas that would cause consternation with any ordinary person. This isn’t to say that scientific formulas are a waste of space, they aren’t. They are of use to a scientist of course, and interesting to those with experience who wish to delve deep. The same principle applies to many hobbies.

The hobby needs science; it is the scientists who explain. The hobbyist doesn’t need to be involved at that level.

Even when avoiding science troubles still arise. The new aquarist, particularly if interested in a reef system, is still faced with gobble-de-gook. There seems to be an unending stream of needs that must be met or failure will occur. Worse, much of this is in shortened version such as KH (for Kelvin), SG (for Specific Gravity), Alk (for alkalinity), temp (for temperature), calc (for calcium), ppm (for parts per million) etc, never mind the variations with lighting; there isn’t a need to go on. Much of this shortened terminology is often used when hobbyists are ‘chatting’ on forums.

Even when the potential aquarist knows what it all means, the problem doesn’t stop. Seawater quality is the number one requirement so the beginner starts to delve into that. The important parameters are discovered but then there are comments on forums and in books about balance – if this is low that will suffer, generating more confusion.

The beginner can flounder at this stage and start to wonder if it’s worth it, it’s supposed to be an enjoyable hobby, at least that is what was understood at the beginning.

The beginner is going to be a successful marine aquarist with some perseverance and if research is done. The research doesn’t need to be into how everything works and what depends on what. The marine hobby has been going for long enough for scientists and advanced hobbyists to have discovered what leads to success. This doesn’t include deep studies into seawater make-up as an example.

It is now well known what ‘high quality’ seawater means. There are tables available that suggest the levels of various items. For example specific gravity is usually quoted as 1.022 to 1.025 for a fish only system, and 1.024 or 1.025 for a reef system. So the aquarist maintains the seawater at the chosen level having considered the given advantages of numbers within the scale. Other parameters are maintained at the levels suggested for them and doing so generally removes the problem of imbalance. It is also known what is not required in the seawater, for example nitrate. Again there are guidelines that suggest upper limits for different systems, so these levels can again be maintained. The beginner aquarist will also have learned of the need for stability and how to achieve this.

So the marine hobby isn’t a scientific challenge for a beginner or anyone else. All that needs to be known are the suggested levels for a marine system, and then maintain them. It should also be said that the system itself needs to be basically adequate, but again these needs are well known and obtainable.

So the mystique is gone. It must be said that patience and a basic understanding are required. The basic understanding is just that, the numbers that represent the levels that livestock require within an adequate system. When this is achieved and maintained, all things being equal success is on the way.

That doesn’t mean to say however that the aquarist never delves into the world of science. Once the ‘bug’ has bitten, some aquarists have to pursue knowledge about ‘why’, and that is to the advantage of us all.

---

Next Page »