How Gallonage Matters

No matter how big or small an aquarium is they all have a gallonage which is often stated in the manufacturer’s documents. Some aquariums are of a standard size and are known as a ‘fifty’ or whatever.

The gallonage quoted in the aquarium name or manufacturer’s documents is with it empty, it has to be this way as of course the manufacturer has no idea of what use the aquarium will be put to and what will be inside it.

As far as the marine hobby is concerned, the quoted gross gallonage can be ignored, it is irrelevant. What is of interest is the net gallonage, the amount of seawater the aquarium can hold once all the decorative whatnots are installed. In the case of both a fish only and reef aquarium, whether live or inert rock is being used doesn’t matter; it is the amount that is installed that does. In the first place, if live rock is being used there must be enough to provide adequate bio-filtration for the full bio load. Secondly, the more there is of either rock type the less the seawater gallonage will be.

If the aquarist decides to use a DSB (deep sand bed) or plenum then this will again reduce the seawater gallonage. A decorative sand bed is not as deep but still accounts for lost seawater space.

So it is important that the aquarist is aware of the net gallonage of the aquarium. Having a sump has advantages and one of these is that the net gallonage is increased.

Calculating the net gallonage could be a hit and miss affair. Probably the most accurate way is for the aquarist to measure the prepared seawater as it goes into the aquarium on the first fill. However, many aquarists mix the initial seawater in the aquarium, but nevertheless a note could be made of the amount that goes in. If any of this first fill is eventually removed because of overfill it needs to be deducted of course. There are helpful gallonage calculators on some marine forums for those who did not measure the ingoing seawater, though accuracy will be lower.

Both the reef and fish only aquarium rely on net gallonage for stocking levels. This is for fish; corals present a much lower bio load. The reef aquarium carries less fish than a fish only system which gives regard to necessary seawater quality. With both systems seawater quality is the number one requirement – how can the aquarist stock correctly if the net gallonage is not known?

When calculating stocking levels for whatever system, the sump seawater should be ignored. The seawater in the sump is not available to the fish and should be viewed as a quality enhancement advantage.

Stocking to the gross gallonage of the display aquarium, or to an overestimated net gallonage could lead to trouble. The aquarium could be and is likely to be overstocked. If there are too many fish there is greater pressure on the seawater quality. In addition it creates more work for the bio-filtration. Further, if there was a temperature increase there could be oxygen problems. The fish obviously require sufficient oxygen, and so does the bio-filter, or rather all the oxygen hungry bacteria in it. If there are problems with the bio-filtration then real trouble could begin.

Also, overstocking can mean overcrowding. Fish will argue and even fight over the right to territory, some more than others. This could lead to fish not eating properly because of stress. On the wild reef fish have plenty of hiding places and in addition if they need to retreat there is plenty of space to do so. Within the strict confines of an aquarium where does a fleeing fish go?

So it is certainly to the advantage of the aquarist and his/her future enjoyment of the hobby to go through a careful initial procedure. This includes research into compatibility with tank mates and aquarium type of course, but should also consider the space that is going to be available. During reef or aquascape construction the aquarist should give full regard to supplying sufficient homes for the number of fish it is intended to keep, many commonly used rocks are helpful with this because they are of very irregular shapes. It will pay off as fish that are settled and secure will be healthy and show the colours that nature intended.

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Algae – Friend Or Foe?

Mention the word ‘algae’ to different marine aquarists and the reaction could be mainly one of two, a look of horror perhaps bordering on panic or a smile and a nod. It all depends.

To some aquarists algae is most definitely a foe. These aquarists are, in the main, novices who are gathering experience and have found out the hard way the consequences of over feeding, over stocking, or over lighting. There could even be a combination. One consequence is long hairy green stuff waving in the currents as though it is making fun of the suffering aquarist. Green filamentous algae can spread to such an extent it overgrows the whole aquarium! It seems to be hardy too, as even if the nutrient level is reduced the monstrous stuff seems to survive for quite a while. It takes the nutrients out of the seawater of course which is the only saving grace I can think of. No, there’s one more, which is that it is food for some fish. Nevertheless, it is not required in abundance.

Similarly, slime alga is a problem. This time it is like thin semi-solidified goo on surfaces which is capable of suffocating the life out of anything it covers, again definitely not required. Fortunately it can be siphoned out at routine seawater changes but tends to linger for a while.

So who smiles at algae? It has to be those aquarists who have control of their aquarium conditions. Seawater parameters are as they should be and not permitted to be anything else. Some of these aquarists use algae to combat other algae, which sounds like justice to me! For example, nitrate and phosphate are implicated in the growth of nuisance algae. The same nutrients are necessary to some decorative algae. So, take some decorative algae, such as the Caulerpa macro type, and grow it in reasonable quantity in favourable conditions. If the bad algae is being physically removed and the good algae is taking in nutrients and in favourable conditions, which will lose out? It is likely to be the bad algae. Many use the system and it is definitely helpful.

Have a look at the imported photo with this text. Is that some of the hairy stuff I see?

I’m going off track a little but remaining with algae. Here’s another positive for algae which could develop beyond the intended stated use in a few years. Hope it proves to be of huge benefit!

http://coast2coastam.net/?p=198

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I Did It On Purpose

This sounds a bit like a confession and in a way it is. I’ve done something that shouldn’t be done and did it knowingly. Fair confession!

Now and again I try to find something out for myself by running an experiment. A scientist would advise that they aren’t experiments at all but amateur fiddling, and I accept that. To qualify as scientific there needs to be a control set up for comparison purposes and various readings taken. All I do is observe for the most part.

I keep a soft coral reef lit by a bank of fluorescent tubes, equally mixed marine white and marine blue.

The last experiment – sorry, fiddling – I did before the current one concerned cover glasses. I don’t habitually use cover glasses nowadays though I used to. They were used as they reduced the amount of evaporation significantly. I noticed in the morning when the lights came on that the cover glasses were heavily condensed underneath, so much so that there were droplets visible all over them. I wondered if this condition would affect the light input into the aquarium and therefore the corals. It took a fair while each morning for the lighting heat (fluorescents) to clear the condensation.

So I took the cover glasses off and noted the date. The cover glasses were left off for a full six months and I watched the corals with care, wondering if growth rates or colour would change.

During the six month period the aquarium was treated as normal, there wasn’t any change in the feeding regime or maintenance schedule. I had to increase the top-up amounts as evaporation increased, but this was expected.

I have to admit to some disappointment as I had assumed that the corals would respond to the increase in light. The light input to the seawater would be affected to some extent by the presence of glass covers even though they were kept clean, and the period each morning when heavy condensation was on the glasses also no longer had any impact on the light. However, the corals showed no change whatsoever, either in growth rates or colour. The growth rates and colour had always been good with the cover glasses on, but, as said, removing them had no effect (accept for the evaporation rate).

The cover glasses have never been replaced as I assume the gas exchange should be better at the seawater surface. Hmm, I wonder. Maybe I could check that someday, though there isn’t any real necessity as the fish are clearly healthy with a normal gill beat.

My latest fiddling has been to do with feeding. I always feed carefully as this is where the phosphate comes from, and a lot of the nitrate is generated. Both are undesirables not least because they are fertilizer for nuisance algae. I haven’t any nuisance algae and never have had.

I have a very low fish load consisting of one Flame Angel (Centropyge loriculus) and one blue damsel (Chrysiptera cyanea). This represents a very low bio-load on an aquarium that has been running for 6½ years (i.e. the aquarium is aged and fully mature). I was interested to see if the bio-filtration, all those hardworking bacteria, could cope with a sudden increase in load.

I used to use canister filters for bio-filtration but fairly recently have removed the media as the rocks are live (when the aquarium started they were dead and inert). The period between that action and now means that any bio-filtration has transferred to the rocks. After the canister filter media was removed there wasn’t a problem of any sort and nitrate didn’t appear (there isn’t a nitrate reducing device on the aquarium nor any Caulerpa algae etc). This shows that the bacteria on and within the rocks cope.

I didn’t want to upset the balance of the aquarium by introducing any new fish, I’m very happy with the set-up which has been very successful. How could I increase the bio-load?

I decided to overfeed. Yes, that’s right, doing that which we say over and over shouldn’t be done! As said previously, I feed very carefully and am fully aware of the fish’s appetites and what is enough. They are fed a basic of marine flake and varying frozen foods, mainly enriched brine and mysis shrimp.

I carried out my normal Sunday maintenance and that evening, when a normal feed was due, I fed the usual amount. At the point when I normally cease to feed, I continued even though the fish weren’t interested. About ½ of the normal amount was fed additionally. This overfeeding continued for a full week and ceased on the following Sunday evening when a feed was due, this feed reverted to normal.

During the overfeeding period I watched the aquarium more carefully than usual, particularly the fish in case there was any sign of discomfort. An indication like this could have signaled the appearance of ammonia and nitrite. There weren’t any negative indications whatsoever.

Mid-week I did an ammonia and nitrite test just to be sure, there wasn’t anything detected. At the end of the week I did a nitrate and phosphate test, again nothing was detected. (It should be pointed out that I continuously run an anti-phosphate filter.)

It is now about 3 weeks since the testing began and nothing has appeared that shouldn’t be there.

Only one indication of the additional feeding appeared, and this was heavier than normal algae on the aquarium viewing glasses. This was not heavy, but there was more. This was easily cleaned off during maintenance.

So I have to assume that the bio-filtration is quite capable of holding its own, though the percentage increase in the bio-load because of the food is…I haven’t a clue! The amount of food put into the aquarium (flake and frozen) was 50% higher than usual. The Baensch Marine Atlas advises that, assuming a protein content of 50%, one gram (about a teaspoonful) of flake can add 336 parts per million nitrates, this is after the nitrogen cycle process completes of course.

It could be commented that there wasn’t an effect as the fish load is so low. Is this correct though? The size of the bacteria populations will be dependent on the demand made upon them.

I was surprised that there wasn’t any effect apart from some glass algae though. I thought bio filtration couldn’t adapt that quickly.

Then I had a further thought. My aquarium, particularly at night, displays a large population of tiny life forms. Any food available that has not been touched by the fish could well have been eaten by them. Nevertheless, the food has gone into the aquarium and the process of consumption would lead to waste. So again the bio-filtration must have coped. It also demonstrated that live rock can complete the full nitrogen cycle, from ammonia to nitrogen gas, thus the lack of nitrate.

As already said, this wouldn’t qualify as a definitive scientific experiment. I found it interesting though, and at the least it gave me confidence in the live rock ability now that the canister filter media is no longer there.

Now, may I point out that my aquarium is very mature and also that I can claim experience. Overfeeding is a definite no-no and should be avoided. Seawater quality is the number one priority and overfeeding will not help at all! I only did it for a week and reverted to careful feeding afterwards.

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A Website To Help Keep Track Of Your Aquarium

There is a website which allows you to keep track of your aquarium online.

The website is called Reefiris and is currently in Alpha mode which basically means that there may be some bugs present and some features which are not yet complete. As the site is in Alpha mode the data entered may be deleted to allow for enhancement, bug fixes etc to be applied.

Once the website comes out of Alpha mode and enters beta stage it will probably be more stable.

To start tracking your aquarium you first need to sign up and then enter details about your aquarium. Once this is done you can start logging parameters, reminder notes etc. The good thing about it is that you get your very own web space where you can see all of your parameters over time in a graphical format (hourly, daily, weekly and monthly). Therefore you can spot trends starting to appear and hopefully react before it becomes an issue.

They also appear to have support for various controllers such as Aquatronica, AquaController etc so if you use one of these the data can be exported straight into Reefiris.

I think that this site has amazing potential and if done right could be an exceptionally useful tool for aquarists all over the world.

Why not go and check it out and remember to keep an eye on it as I’m sure it is going to improve.

http://www.reefiris.com/

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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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What Salinity Should I Keep My Marine Aquarium At?

Marine aquarists use a hydrometer to measure the specific gravity (SG) of the seawater. The hobby hydrometer is not a pure scientific instrument but is capable of sufficient accuracy to enable stability of the SG – provided the aquarist does at least a weekly check.

Marine aquariums come in two main types, fish only and reef. To be precise, for ‘reef’ I should really say mixed reef and corals only reef, the former being corals and fish (the usual).

The first consideration is what SG is really necessary. To answer that it would seem best to look at the wild reefs, our livestock’s natural home. The SG of the sea in those locations should give the answer. Well, yes it should, but it doesn’t seem as simple as that. Is it ever!

The sea is considered to be stable which for the volume taken up is not really surprising. The SG on the reefs though is perhaps surprising, as it can range from 1.017 to 1.031*. Specific gravity is affected by temperature and some variance in temperature is understandable. In addition, some seas are more ‘land-locked’ than others such as the Red Sea. So there is going to be variance.

Some state that it is best to mimic nature and I sympathize with that. However, mimic which reading?

Looking at averages could be the answer. The lowest encountered salinities (on reefs measured) had an average of 1.025, and the highest 1.026*. Now this is more like it.

Provided livestock are acclimatized properly there is tolerance to some change which over a period becomes the normal. Generally, fish are like this and will happily live in seawater with an SG from 1.022 to 1.026. (Some aquarists use lower SG levels for specific purposes.) There seems little point in having a higher SG than necessary so many fish only systems run at SG 1.022. There is some evidence that certain parasites don’t do so well at 1.022 so that is a bonus. Also, and very much secondary, not so much dry salt will be required for routine seawater changes which will reduce costs a little.

What of the reef system? Whether this is corals only or mixed, the corals dictate the SG requirement. Corals are much less tolerant of a lower SG and 1.024 is the minimum for them. The range usually cited for corals is 1.024 to 1.026.

Whatever the seawater SG is, it should be stable. Testing at least once weekly is required and unlike many other types there will not be a need to renew a test kit from time to time. The hydrometer, barring accidents, is a once only purchase.

SG is a very important parameter of seawater and one that is very easily controlled. The SG could reduce because of salt ‘creep’, where salt encrusts overhead wiring, lights, glass and the like. The SG could increase because of poor seawater top-up management, as only fresh water evaporates leaving the salt behind. High quality seawater is the often quoted number one necessity and simple monitoring is required.

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

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