Cool It

The most popular lighting for reef aquariums, or to be more specific SPS reef aquariums, continues to be metal halide. This is because metal halides emit a very intense light that has considerable seawater penetration strength as far as aquariums are concerned. Metal halide bulbs are also available in the Kelvin range desired by reef aquarists.

There are two major disadvantages to metal halide lighting systems, the first is cost as they are electricity hungry. The second is heat emission which could be a problem in itself or cause a minor problem to become a major one.

With air temperature warming up for the summer the heat emission from the metal halide bulb(s) doesn’t alter, but the increased air temperature does mean that the aquarium seawater will naturally warm up. This in itself isn’t a bad thing as the heaters will not activate as much saving the aquarist money. Unfortunately, heat output from the lighting can increase the seawater temperature even more, moving it passed the design level. The heaters will of course not activate but these high temperatures are detrimental to the aquarium, for a start it upsets the stability of the system. Increased seawater temperature also reduces the amount of oxygen the seawater can hold, so in say a heavily stocked fish only aquarium there could be trouble. If temperature climbed excessively trouble could occur in any aquarium system. The bacteria housed within the bio-filter that are dealing with the toxins in the seawater are also consuming oxygen which could exacerbate the situation.

So overall it is undesirable for the seawater temperature to climb excessively. There are ways of cooling things down though and with metal halide this is a need that is more likely to be encountered.

Some aquarists counter the effect of the metal halides by cooling down the seawater itself. They do this by employing a chiller (a cooler) which must be specifically designed for marine use because of the very corrosive action of seawater. The chiller needs to be sized correctly or it could be ineffective, a check needs to be made to ensure the device is able to deal with the gallons of seawater involved and also the temperature reduction required – as far as the latter is concerned, if the chiller is matched to the gallonage it should be adequate as there is a temperature adjustment range.

There’s nothing really wrong with using a chiller as described. However, if the sole use of a chiller is because of the heating effect of the lighting it is not really economical. The lighting is consuming electricity which cannot be avoided (except to ensure the bulbs are correctly sized and the lighting on period is not excessive). A chiller is quite an expensive piece of equipment and quite expensive to run. If the seawater heats up anyway quite apart from the lighting fair enough.

If it is mainly the lighting that is causing the seawater temperature problem it is better to tackle the problem at source. Some free hanging metal halide canopies have fans built in which help direct the heat away from the seawater. The biggest problem is likely to be found with those lighting systems that are enclosed within a hood which sits directly on top of the aquarium. These canopies are often an ‘all in one’ build with the canopies matching the aquarium stand.

If the canopy is as described it could have been supplied commercially or been a DIY project. Commercial ones sometimes have fans built in, but not always. Some have air vents at the top and that’s it. These air vents do release heat as warm air rises, but the heat release is too slow and doesn’t deal directly with heat into the seawater. Fans are reasonably easy to install.

There are two ways of installing the fans; the first is to have two fans, one at each end, with an air vent in the middle at the back, and the second is again to have two fans but no air intake at all. In the second version an air vent could be fitted either in the middle or above, it will not do any harm. The idea is to direct a cool air flow across the space between the metal halides and the seawater surface.

Metal halide canopies are of necessity quite large with a good space above the seawater surface, so there should be plenty of room to fit a fan at each end. Some aquarists use computer type fans but the danger with these is that they may not move enough air to deal with the heat. A better option is to use mains electricity powered fans. The ones that are useful are those smaller units that are fitted into bathrooms as extractors; they are usually a small plastic box with vents each side and the fan already mounted inside. Some of these type fans are reversible, that is the fan direction and therefore the air flow can be reversed. If two of these fans are obtained one can be fitted at each end of the lighting canopy. Two holes will obviously need to be cut but if the edges are a little ragged the fan units could fit on the outside to cover them up, the units need to be checked for this option. Some units have a removable outside cover which also fastens the main unit on the inside securely.

In the first option the fans are fitted and there is an air vent in the middle of the canopy back plate. The fans are set so that they both suck in cool air from outside the canopy. This causes an increase of air pressure – not a lot – inside the canopy and the air escapes through the air vent taking heat with it. Care has to be taken that the air doesn’t escape downwards towards the seawater or the cooling effect could be partially or wholly lost.

The second method, with or without an air vent, is probably the best. The fans are fitted at each end of the canopy but this time one fan, it doesn’t matter which end it is at, is set to suck air in. The opposite fan is set to blow air out. This means that there is a powered cooling air flow through the lighting canopy. If there is an air vent some air could escape, but again heat will go with it.

The paragraphs above are concerned mainly with metal halide lighting, but those aquarists who have fluorescent lighting such as T5’s or earlier types could be surprised at how much heat actually builds up in the canopy. A fan cooling system could be an advantage.

There is a major point that needs to be mentioned and this is concerned with safety. Electricity incorrectly used is dangerous. The fans need to be securely fitted and not subject to splashing. Wiring to the fans needs to be completed safely, with the wires going to correctly fused power outlets, and the wiring obviously needs to be properly secured, not trailing. Any doubt and advice from someone competent should be obtained.

Preventing the lighting system from overheating seawater is generally simple and can be done in a way which minimizes the additional electricity demand.

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I Know About Seawater Quality, But…

Marine aquarists aim to maintain seawater which is of the highest quality. The reward for doing so is a vibrant aquarium, be it a fish only, corals only or mixed reef, and without the intrusion of nuisance algae.

‘Quality’ means the seawater is stable, the pH in the region 8.0 to 8.4, nitrates in a fish only at 30 ppm (parts per million) or less, in a reef system 10 ppm or less, and phosphate preferably undetectable. If the aquarium contains a captive reef the aquarist will quite likely maintain alkalinity, also calcium if this is relevant to the livestock. However, for the purposes of this discussion quality means stable pH and ‘proper’ nitrate and phosphate levels, that is, they are within the guidelines.

Aquarists complete routine seawater changes which go a long way towards maintaining high quality. Any undesirables in the seawater are diluted and, at the same time, trace elements are replenished or partially so. The seawater could be said to be freshened. The initial guideline amount for routine changes is 10% of the total net gallonage of the system weekly. This therefore includes any sump. There isn’t any requirement to change 10% every week; the aquarist could find it more convenient to change 20% fortnightly. However, a weekly change probably contributes to stability in itself, as the change caused by raw seawater being added is smaller.

pH as said could be anything between 8.0 and 8.4. Whichever the measurement is it should be reasonably stable. It is possible, in some circumstances probable, that there will be a fluctuation in pH between the lights on and off periods. This is normal as it has to do with seawater dissolved gas levels. If there is an excessive reduction, or any reduction which worries the aquarist, one way of combating the change is to employ algae in a sump. The macro algae Caulerpa is commonly used and is lit by fluorescent tubes which have an opposite cycle to the display aquarium lights, which means that when the display aquarium is lit the sump is not and vice versa. Plant growth tubes are often used to assist the Caulerpa, these tubes have a lower Kelvin rating than lights commonly used on a display aquarium. The Caulerpa will also act as a natural filter to combat nitrate and phosphate.

Sometimes pH is not varying excessively, it is just too low. If the reading is consistently too low, and by this it is meant below 8.0, then it is possible that the system does not have efficient enough gas exchange. Gas exchange occurs at air/seawater interfaces, particularly at the aquarium surface. It also occurs on protein skimmer outlets, weirs and the like. It is at these interfaces that the seawater takes in oxygen which is clearly important for livestock. Too low an oxygen level could have serious repercussions for the livestock under certain circumstances, and it could also be the cause of a low pH reading.

Testing the seawater for sufficient oxygen relevant to pH is very easy. Measure the pH of the seawater in the aquarium and make a note of the result. Siphon a gallon or two of seawater into a safe bucket, the one used for new seawater will do. Importantly maintain the temperature so it is the same as the aquarium and also circulate the seawater vigorously for two hours or so. The heater used for new seawater will be fine, also the powerhead or air pump. Note that the seawater needs to be moved vigorously, if it is sluggish it will not do.

After the required time measure the pH of the seawater in the bucket. If it is the same as the aquarium then seawater movement in the aquarium should be adequate. If the pH is higher than that in the aquarium then increasing seawater movement in the aquarium should be beneficial. Sometimes an additional powerhead will do. Place it about half way down in a convenient and hopefully hidden from view spot, and point the outlet at the surface or at an angle across it. Seawater will be moved either in a mound at the surface or a stronger flow will move across the surface. In either case gas exchange should increase affecting the pH. Before an additional powerhead is used it could be worthwhile checking the positions of existing devices.

If the pH is too low and the above test doesn’t make any difference, maybe the alkalinity is also too low. Keeping it brief and basic, seawater is on the alkaline side of the pH scale. Life actions of livestock continually try to push the pH towards the acidic side, particularly in heavily stocked fish only systems. Increasing the alkalinity could maintain pH at a more desirable level and is worth trying. If alkalinity is adjusted it is usual to keep it above natural seawater levels. If it is intended to try this, then there isn’t any mystery or need to explain measurements. Test kits and adjustment powders are commercially produced and easily obtained. The instructions will explain all and there will be a measurement chart included.

The aquarist could be having trouble with nitrate and/or phosphate. If routine seawater changes are properly done and excessive readings persist there are checks that should be initially considered.

First is feeding as this is the major culprit in many seawater quality problems particularly with novices. Nitrate is a product of the nitrogen cycle and is the end product with a canister filter. Even the acclaimed live rock cannot deal with some nitrate readings. Phosphate is mainly introduced to the seawater by feeding. Both nitrate and phosphate have been implicated in problems with nuisance algae, so excessive readings need to be reduced. There is information on feeding techniques in the Articles section on aquaristsonline.com, so further explanation will not be given here. The tendency to overfeed usually has two causes, the first being the pleasure of feeding and the second the concern that the livestock get enough. Both are good reasons, but the act of overfeeding will do harm. As said, the first action is to carefully check the method of feeding and the amount fed.

Nevertheless, some aquarists have trouble anyway, despite being disciplined when feeding and despite doing regular seawater changes. It has already been stated that the initial guideline for routine seawater changes is 10% of the total system net gallonage. Note the word ‘initial’. It may be that the amount changed needs to be increased. It could very well depend on the livestock load. A fully and correctly stocked mixed reef system will usually have a lower bio-load than an equivalent sized fully and correctly stocked fish only system. Fish present a heavier bio-load than corals. So for example in a fish only system there is heavier feeding because of the higher number of fish and of course the fishes life cycles continue. Thus there is more scope to see excessive nitrate and/or phosphate readings. The answer here is probably dilution. In other words an increase in the amount of seawater changed routinely. If the aquarist is changing 10% this could be increased to 15%. Have the readings begun to subside? The readings will gradually subside, as additional pollution continues to be produced – it will not suddenly or quickly disappear. If not, try a further increase to 20%. It is not normally recommended to change more than 25%.

It has to be reiterated that increases in the gallonage of routine seawater changes come after the aquarist is fully satisfied that other avenues to solve the problem are exhausted, such as the mentioned feeding. It is also important to examine carefully the filtration which in the first instance should be adequate. Filtration to combat nitrate and phosphate could be increased. In the case of nitrate more live rock for example, and/or if there is a sump the introduction of a DSB (deep sand bed) and perhaps some Caulerpa algae. In the case of phosphate perhaps an anti-phosphate resin filter could be considered.

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If Seawater Tests Are Fine But…

We are often going on about the quality of seawater and we believe quite rightly so. Seawater quality is the number one priority, no matter what type of aquarium it could be, fish only, coral only, or mixed reef.

Of course, even if seawater quality is correct there could still be problems. Fish need to receive the correct nutrition, and there needs to be a general lack of stress. There are more. However, as said, seawater quality is the number one and regular tests should be made.

Though it doesn’t affect a fish only aquarium anywhere near as much, lighting is number two on the list. This applies to a reef system whether corals only or mixed. This high priority for lighting is because of the needs of the corals. Within most corals are zooxanthallae, single celled algae which are essential to the corals’ wellbeing.

So there’s a problem with the corals? Seawater tests indicate nothing wrong? What could it be?

The link is to a text supplied by aquaristsonline.com which could be of interest in the above context.

http://www.thereeftank.com/blog/look-after-the-lighting/

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Seawater Bath At Midnight!

My wife and I arrived home quite tired after a great day out. We watched some TV and then went to bed.

It is unusual, particularly for my wife, for us to go to sleep straightaway as we are bedtime readers. My wife eats books and reads until the early hours, I tend to get through a few pages before the book hits the floor as I fall asleep.

About an hour on – I realized the time lapse later – my wife shook me awake. I’ll call it awake anyway, more like an eyes partly open stupor.

My wife told me she could hear a peculiar noise outside. Assuming quite understandably that she meant outside the house I replied that it would probably be a cat, or a dog, or something, generally showing a lack of interest.

I was advised that I was wrong. Well, I’m used to that, it seems I sometimes am to the female boss. Apparently the noise was outside the bedroom, not outside the house. Ok, replied I, still not particularly concerned. I mean, sleep is important isn’t it. Our floor upstairs tends to creak when there’s a temperature change anyway. I suggested it wouldn’t be anything important.

My wife got out of bed at this point and went to have a look. Must be concerned I thought. Still didn’t vacate a very warm and comfortable bed though.

Then I got shaken again, to be advised that the problem was the water. Never one to be slow on the uptake, I repeated the word ‘water’. It was then confirmed that yes indeed it was water. In fact it was my aquarium water.

Aquarium water! My eyes opened fully, probably staring in an uncomprehending way.

My wife said there was a fountain of aquarium water shooting up in the air and the hall carpet had been soaked, the information sounding like a news disaster report.

Now there was action! Aquarium water shooting out of the aquarium, what on earth was this? Out of bed I came like a greyhound. Salt water was spouting out of the aquarium in a small arc as though emitted from a hosepipe, rising about 9 inches into the air before landing on the carpet, which was really soaked over quite a wide area.

I was on my knees in an instant checking the seawater level which had fallen significantly but not enough to cause major trouble. Immediate action was needed to stop the pump causing the seawater loss. The seawater was running down the front of the aquarium and the aquarium sits on a stand which is enclosed except for front opening doors. The plugs to all the equipment were behind the doors at the back of the cabinet. Only one thing for it, open the doors and pull the plug out. So I did. At this point I could hear my wife’s laughter, she was standing behind observing the picture of me kneeling in front of the aquarium with seawater pouring onto my back. It must have looked as though this aquarist had finally lost the last marble and decided on some fun.

It took a long time to dry the carpet out as far as possible using as many dry towels and similar items that we could find. Thankfully after about a week the carpet dried without marks. Good job as well, it had only been fitted a short time before.

The cause of the problem was very clear when an examination was made. The problem was me, pure and simple. The powerhead in question had a short outlet pipe as is normal and onto this some flexible tubing had been fitted. However, the piece of equipment the powerhead was feeding fitted a larger diameter tube. The solution at the time was to push the smaller tube into the larger one as it seemed a tight enough fit. When tested there seemed nothing amiss.

The joint must have been coming apart slowly for a few months; the problem occurred about 5 months after the aquarium started up. The joint was checked after the first week or so and then left.

After the problem I fitted a plastic reduction joint that I found at the local garden centre, it was actually intended for pond use. The tubes were now properly fitted and haven’t given any trouble since. The incident was around 5½ years ago.

So it was clearly my own fault, the joint should have been fitted in the first place. I also assumed all would be well, this was wrong. We learn by our mistakes. Don’t assume.

In retrospect I was pleased an electrical safety trip had been fitted.

And a big thanks to my wife!

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I’ve Come Home To No Electricity!

Nothing ever works as it should do does it?

I came home from work today to find that we had no electricity. A quick check showed that we had electricity with the exception of the kitchen and the dining room which therefore meant that we had not had not had a complete power outage but something else must have happened.

My wife was panicking as she wanted to make dinner which put me in a bit of a pickle – food or aquarium!

The aquarium came before my stomach and rightly so.

A quick check showed that a breaker had gone. A quick flick and power was returned. The breaker stayed open so I have no idea what caused it to trip but at least power was restored and my wife was happy as she get on with cooking dinner.

Everything in the aquarium sprung to life – water pumps started pumping, the skimmer starting skimming, lights came on and everything was back.

Looking at the clock on the oven it showed that the power had been off for just over three hours.

Enough time for water to cool down but I am luck as I have a UPS (uninterruptable power supply). This is basically a big battery which when electricity is available passes the power through to whatever is plugged into it. When electricity is not available it powers the relevant devices using it’s batteries and when power is restored the batteries recharge.

As I work in the IT industry I was able to obtain one of these many years ago.

I only have the heaters and the return pump plugged into the UPS as this allows me to protect the aquarium inhabitants whilst providing the maximum amount of battery time as possible. This allows me to keep the aquarium water warm, keep water moving through the sump and provide a small amount of water movement in the aquarium.

The UPS I have with the devices I have plugged in gives me just over 5 hours of battery life before the batteries become exhausted so I had a few hours left on it which was lucky as if it had happened earlier in the day the batteries would have run flat and then I could have been in trouble.

I might have to get a larger UPS when one next becomes available at work which if large enough could run the aquarium for a day or more.

This is the first time that the UPS has ever been used so it goes to show that having a device which you may need at some point is a useful addition.

Just need to get an electrician now to check the wiring out and attempt to locate what cause the issue!

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Are There Any Disadvantages In Using Reverse Osmosis Water?

Marine aquarists, particularly those running a reef aquarium, in the main tend to avoid the use of tap water. This is because tap water quality varies quite a lot depending on where the aquarist lives.

In agricultural and/or industrial areas the water may be affected by nitrates, pesticides, heavy metals and the like. In addition bacteria, viruses and spores (example fungal) could be present though these are much more unlikely.

Water authorities have to be sure that the water is safe for human consumption and therefore abide by standards set down for the maximum amount of any substance that can be present. In addition after treatment the water is kept clean by the use of chlorine. Chlorine also helps keep the delivery pipe work clear of bacteria etc. Chloramines are sometimes used on occasion, when a controlled amount is pumped through the pipes for cleansing. In some areas fluoride is mixed into the water as it is said (not without argument) that it is good for teeth.

The tap water may be fine for us humans but we don’t want any of the ‘extras’ in our aquarium seawater. What we want is seawater that is as pure and natural as possible. Dry sea salt is not cheap and it is not logical to pollute the carefully balanced mix with ‘polluted’ tap water.

95%+ pure fresh water from the tap is achieved by using a reverse osmosis (RO) unit. There are other ways but the RO unit is probably the best way for aquarists. Tap water pressure is used to force water through a sediment filter (this is not always present), then a carbon filter where chlorine is removed (chlorine is very detrimental to the next stage), then through a membrane where very nearly only pure water can pass, unwanted substances cannot. Some RO units also incorporate a final cleaning stage using exchange resins, where any final pollutants are removed. This final stage is not absolutely necessary.

So that’s the answer for the aquarist wanting to mix the highest quality seawater, use an RO unit.

Hang on a minute though, there’s usually some kind of disadvantage.

There is and with the RO unit it isn’t really cost as it can be with some equipment. RO units that are well made and functional are available at reasonable prices. It isn’t locating the equipment either as an RO unit can be hidden away in a cupboard close to an incoming water main, placed under the sink, in fact placed anywhere as long as a mains water supply is within reach and there is space available for a collection bucket. There isn’t a cost disadvantage in using the RO unit as with heaters or metal halide lights as they are not electrically driven. Maintenance is usually wide spaced and not a problem (maintenance requirements are subject to the amount of water passed through the unit and the condition of the tap water before treatment).

The disadvantage with the RO unit is linked to performance. This isn’t to say that they are inefficient, far from it, at least as far as the quality of the useable water is concerned. It is the water that is unusable that is the disadvantage.

When an RO unit is connected to the mains water it produces two outputs. One is the purified water (the permeate) that the aquarist collects to use in new salt water mixes and for evaporation top-ups. The other is the unwanted water (the concentrate) that contains all the impurities (solutes) that could not pass through the membrane. The ratio of concentrate to permeate is about 4 to 1. In other words, for every 4 gallons of unusable concentrate there is 1 gallon of useable purified water.

Some aquarists are not too keen on this ‘waste’. However, it is a straightforward exercise to arrange collection of the concentrate in a larger container. The container need not be of high (food) standard as the water inside will not be used for any human or aquarium related purpose. It could be used when needed in a garden for watering, as an example. With a small aquarium the required amount of purified water and therefore waste water may not be seen as a problem, but with a much larger one it depends on the attitude of the aquarist.

The advantages of using purified water from an RO unit for marine aquarium purposes have I think been well demonstrated.

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Should You Go ‘Sumpless’ Or Not?

Many aquarists have a sump attached to their display aquarium. The numbers that have a sump seems to advise that the answer to the title question is ‘Don’t go without a sump’.

In fact there isn’t a requirement to have a sump. There are a good number of marine systems that do not have one and they are successful. This applies to both fish only and reef aquariums. There are articles on aquaristsonline.com that suggest a basic kit list and a sump is not included. So why then do so many aquarists use them?

A sump is another seawater container that is often placed beneath the display aquarium though it could be elsewhere provided that gravity is available to feed seawater to it. The sump is more often than not another and usually smaller aquarium. Normally an overflow in the display aquarium is connected to pipe work that carries the seawater down, and the seawater is lifted back up to the aquarium by a pump. The guideline for the speed seawater moves through the sump is the system net gallonage times three.

The size of a sump is simple to calculate, it should be as large as is practical. The larger it is means that it will contain more gallons and that is the first advantage. With a sump the gallonage of the system is increased, which is good for seawater quality. The gallons held in the sump should not be used in any stocking calculation as this would negate the quality aspect of the extra gallonage and, with fish, there is the danger that the physical area of the display aquarium would be overloaded resulting in disputes and aggression.

Heaters and a protein skimmer intake are not exactly natural looking in the display aquarium, though many aquarists manage to reasonably hide them. If a sump is available the heaters can be placed in there and a skimmer can stand alongside, in or hang on. This removes the ‘eyesores’ from the display area and probably makes them more accessible. The protein skimmer in particular needs to be easily accessible for regular maintenance.

The usefulness of a sump doesn’t stop there. Seawater filtration is very important and the move nowadays is towards natural methods. Live rock is a good example. Using a deep sand bed (DSB) or plenum (a raised sand bed) is a good partner for live rock offering good additional filtration, and the best place to locate such a sand bed is in the sump. The guideline for the area of a DSB is 2/3rds of the display aquarium base area. This isn’t always achievable so the largest sump that will fit is again an advantage. The DSB is deep, hence the name, but this doesn’t stop the heaters and protein skimmer intake from going in the sump as well.

Still on the filtration theme, some aquarists grow the macro algae Caulerpa in the sump, which is designed as an aid to filtration and seawater quality. The Caulerpa will help remove, among other things, nitrate and phosphate. These two are implicated in the growth of nuisance algae.

The sump should not be used as a refuge for a sick fish as it forms part of the overall system seawater gallonage. For a fish suffering from excessive harassment it could be a temporary home.  Also, if a life form appears that is unwanted the sump could again be used as a temporary home. A Mantis shrimp for example.

There isn’t a requirement to have a sump immediately the system is set-up, although this is really the better way to go – have the advantages from the start and avoid moving equipment later. A sump could be added later and in this case it is advantageous to consider it at the design stage. Though there are siphon based overflow boxes available, the best way of getting seawater to the sump is into overflows and down pipes. This requires a hole or holes in the display aquarium. These should be drilled before the system is set up. If they are not going to be used straightaway they can be temporarily covered.

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