Seawater Changing

It can be a reef aquarium or fish only aquarium, large or small, but whatever it is there is a need for high water quality. When an aquarium system has been running for a time, the water quality can start to fall.

Good husbandry practices can slow down the drop in the quality of the seawater. Efficient bio-filtration, protein skimmers, perhaps activated carbon, calcium reactors, reverse osmosis top-ups etc all assist. Nevertheless routine water changes are a great aid.

Many of us aquarists are not particularly scientific or technical, but nevertheless it seems obvious that the seawater that filled the aquarium is not going to remain in the same state. The life forms in the aquarium see to that. Their life functions change the seawater state - an example is the pressure on pH. Acidic pressures caused by life forms try to reduce pH, and it is only the buffering capacity of the seawater that resists this. If this buffering capacity, or alkalinity, fails then the pH will be in trouble. So for a start, particularly in a reef system, alkalinity needs to be monitored. This of course isn’t the only change that occurs.

The general guideline for the amount of seawater to change is 10% weekly. This should start as soon as the system is active. By changing routinely the seawater is freshened, and trace elements partially replaced. The possible slow build up of nitrate (and other unwanted items) is reduced.

The 10% guideline is a good starter point, particularly for beginner and inexperienced aquarists, who simply need to know ‘what to do’. Once experience is gained and the trends of the aquarium are understood, then, with care, the replacement amount can be reduced. In some cases it may need to be increased, often because of nitrate worries, which in turn is often because of overfeeding. Overfeeding is a pitfall beginners could fall into. It doesn’t take long to realise the error though. If the amount of seawater changed is being decreased, the amount mixed and placed in the aquarium can be the same but at wider intervals, for example every two weeks instead of weekly. Or the weekly change could be reduced of course.

If the routine change is being altered it is important to monitor the seawater parameters. This can be relaxed up to a point when the checks on quality show that all is well and consistently so.

It doesn’t happen often because dry salt mixes are expensive, but aquarists have been known to do large or very large changes in the belief that it ‘must be doing good because it is fresh’. This has been known with nano systems where a large water change (relative to the capacity of the system) is easily done.

A new seawater mix is heated to the temperature of the aquarium seawater and also mixed with an airstone or a powerhead for around 24 hours before it is used. This is to ensure that the salt has mixed completely, and it is fully oxygenated.

There is more to it than that though. The new seawater is still ‘raw‘. The seawater needs to age and this occurs when it is in contact with all the various influences that make up the captive environment - fish, corals, bacteria, tiny reef life, algae etc. This only occurs within the display system, not in the mixing bucket.

So large water changes done routinely are not good. The change gallonage should be tailored to the needs of the system, and the need is discovered by careful testing and a watchful eye.

In my opinion, all systems should have seawater routinely changed. I believe I’m correct in my belief that the majority of aquarists agree.

There are occasions when a larger water change could be beneficial. For example, a fish only system may have been dosed with copper to fight a disease. At the end of the treatment, activated carbon could be used to clear the seawater. Following this the carbon is disposed of and a larger than normal seawater change completed. This change should not be over large, say 20%. If necessary, the change could be done in two goes spaced a few days apart if the aquarium system is a big one.

Nitrate is a problem in quite a few systems, and aquarists advise doing large water changes to try to reduce the level. It is right to try and do something about excessive nitrate but large water changes are not the best way. They may be a temporary solution.

Nitrate only appears if there is something to generate it. Again, feeding is a regular culprit, and it may be that the aquarist is causing, or partially causing, the problem. There are other potential causes. The need is to discover the reason and rectify it, not reduce the problem by large water changes.

Water changes (of normal proportions) take longer to achieve the dilution result than might be thought. The link below is interesting for anyone who wants this explained. The author uses a nitrate problem as an example, along with others.

http://www.reefs.org/library/article/t_brightbill_wc.html

So routine seawater changes are necessary because they are beneficial. It was, I think, the aquarist and researcher Dr Ron Shimek who found that seawater in a captive system was quite unlike real seawater. Our seawater remains ‘natural’ enough as fish and corals thrive in it, and it is clearly necessary to do all that is possible to keep it that way.

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Tags: Aquarium Maintenance, Aquarium Water, Care, reverse-osmosis, saltwater, Water Quality

Water Hardness - What Is It?

Water hardness in the marine aquarium is important. The term ‘water hardness’ is maybe too general. It would probably be better to call it carbonate hardness. Another term that is perhaps more recognised in marine hobby circles is alkalinity.

In the sea, the measurement is around 8 dKH (or 2.9 meq/l). This is all starting to sound a bit technical, but it isn’t. All that is really required is for the aquarist to know what the measurement represents, what level should be maintained, and why it is important.

In the sea, there is hardly any change in alkalinity because of the huge volume. In the aquarium it could be a different matter.

Marine aquarium stock carry on with their normal life functions of course. Some of these functions and waste that get into the seawater apply acidic pressure to the seawater. This acidic pressure is constantly trying to lower the pH. (A pH of less than 7 is on the acidic side, 7 is neutral, and above 7 is on the alkaline side.)

As known marine aquariums run from pH 8 to 8.4 for the most part, the ‘perfect’ pH is usually quoted as 8.3. Therefore it can be seen that seawater is alkaline. That’s where it wants to be and where the aquarist wants it to stay. Measuring alkalinity now makes a bit more sense.

Reduction of the pH by acidic pressure is resisted by the alkalinity of the seawater. This is achieved by the carbonate/bicarbonate content. If the aquarist goes to a marine retail shop, there for sale will be additives called alkalinity buffer, pH stabiliser, or something similar. These are carbonates/bicarbonates that are added to the seawater to maintain or increase alkalinity.

The acids that are being added to the seawater are negated by the alkalinity, and the pH is protected against unwanted shifts. However, alkalinity is not constant and can be reduced or even exhausted. As said the seas and oceans are huge, but in an aquarium the acidic pressure could show itself. Routine water changes assist in preventing this. It is considered to be better in a captive system to maintain the alkalinity something higher than natural seawater, and the measurement can be between 9 and 11 dKH (3.2 meq/l to 4 meq/l).

My seawater is maintained at an alkalinity of 3.75 to 4 meq/l. It drifts down during the period between water changes, and is boosted back up (along with the water change). This appears to have assisted in the growth of desirable encrusting algaes and maybe therefore in other life such as snails etc, of which there are many.

Many aquarists do not concern themselves much with alkalinity. This is fine if the livestock is thriving and the pH is as desired and stable.

There are available commercial test kits for alkalinity and they are simple to use. The test kits usually provide a conversion scale to read from, so the aquarist doesn’t have to know what the measurements are scientifically, just what they are of, and the desired level. If an aquarist finds it necessary or just wants to know, this parameter is easily discovered.

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Tags: Aquarium Maintenance, Aquarium Water, Care, saltwater-aquarium, Water Quality, water tests

What Is The Best Salinity To Keep A Saltwater Aquarium At?

The salinity of the marine aquarium is one of the major parameters that must be routinely checked. Salinity can change because of evaporation, and it is important to keep it stable. Daily top-ups of the water to a pre-determined level is an easy way, or using an auto top-up device.

Aquarists normally deal with specific gravity (SG) which is a straightforward measurement to obtain. The instrument used is a hydrometer, normally of the swing needle or floating needle type. They are both accurate enough for hobby purposes, and any small inaccuracy can usually be disregarded as long as the measurement is stable.

On the wild reef the salinity measures an average 35 parts per thousand (ppt) *. 35 ppt is the equivalent of close to SG 1.026. It would seem therefore that an SG of 1.026 should be maintained. There are many aquarists who consider this to be correct, stating that mother nature knows best. These aquarists include several well known names, and they are concerned with captive reef systems.

The fish only aquarium can be kept at a lower SG. In the many years that aquarists have kept fish only systems, and remember these existed well before captive reefs, it was found that there were advantages in maintaining a lower SG. First of all, there was evidence that certain fish parasites do not do well at a lower SG. This is supported to an extent by one method of dealing with parasite infected fish - lowering the SG to destroy them. However, the SG being considered here is not as low as that. The level is 1.022. This will mean that the fish hopefully will not fall foul of parasites so easily, and the cost of salt to the aquarist will be lower (though the cost is not the most important consideration). It has also been stated that the marine fish natural bodily function of water transference is less strenuous. There is no evidence that maintaining fish at a lower SG is detrimental to them.

SG in a captive reef system is not so straightforward. A higher SG should be maintained as there is evidence that some corals may not open polyps in a lower one. Corals are also stressed over the long term by a too high or worse too low SG and could even die if the situation was allowed to continue. As said this is long term - changes in SG of a short duration, though very undesirable, will not have the same result. It is reported that soft corals are more influenced by incorrect SG *.

I have a soft coral reef that I do not maintain at 1.026. It is maintained at 1.024. This level does not fluctuate by any amount to speak of. The corals are healthy and growing and there are, and have never been, any signs of stress.

So, an aquarist keeping a fish only aquarium can safely reduce the SG to 1.022. There is no reason it could not be higher, after all the fish live in the wild at a higher level, but it is well known that a lower SG will do no harm.

Where there are corals involved, it will be best to maintain a higher level of 1.026. The aquarist with the confidence of experience can lower this SG very carefully over a lengthy period, and note if there are any bad reactions by the corals. If there are, the SG must be raised, again over a period. Sudden changes are not wanted. If there are no bad reactions, then SG 1.024 is probably the lowest that should be maintained.

If aquarists are able to take their swing needle or float needle hydrometers to somewhere that can test the accuracy against a known correct measure, all the better. The aquarist can then add to or take from the required measurement on their hydrometer to obtain more accuracy.

( * Reference: Eric Borneman. Aquarium Corals)

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Tags: Aquarium Water, home-aquarium, marine-aquarium, saltwater-aquarium, Water Quality

Aim For Excellent Water Quality And Your Fish, Corals Etc Will Thank You For It

The title of this post is a saying which my father has said to me ever since I first started in this hobby. Where he got the saying from I don’t know - maybe he made it up himself.

How true this saying is though.

It does not matter if you are an absolute newbie to this hobby or have been keeping a saltwater aquarium for a while the aspect which we should all be aiming for is corals, fish, invertebrates etc which are happy, well fed, safe and content. To ensure this we need to ensure that optimum water quality is achieved.

For beginners and quite often advanced aquarists this is an area which I believe is quite often neglected. A lot of effort is put into researching what equipment is required, how the equipment works etc that they sometimes forget how and why water quality is such a requirement.

There are some great books which can be read on this subject, some great web sites (of which Aquarists Online is hopefully one) where this can be learnt and there are experienced aquarists who are prepared to assist in learning this.

If you think about it the reason we have all of the equipment in and attached to the aquarium the majority of it is to remove aspects from the water, put things into the water etc. The end point is good water quality.

Just because you purchase all the equipment however does not mean that you are definately going to get good water quality. Every aquarium is different and every aquarist is different.

Research why excellent water quality is such a high requirement in a saltwater aquarium and then learn how to achieve it.

We are here to help - why not leave a comment below and tell us which aspects you are struggling with.

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Tags: Aquarium Water, home-aquarium, marine-aquarium, saltwater-aquarium, Water Quality

Consider Using An Auto Top Up Device

It always surprises me how much water actually evaporates from a saltwater aquarium. It does depend upon the aquarium of course, how much water movement there is on the water surface, if overflows are used, the type of lighting selected etc.

As we know stabilty is required in a saltwater aquarium. Stability of salinity again is very important. When the water evaporates the salt is left behind and the specific gravity can slowly rise. If water is not topped up then the specific gravity reading of the aquarium when checked will be wrong.

If you do not use overflows and use fluorescent tubes for lighting then probably you will be able to maintain control of the water top ups required due to evaporation. It could be twice a week, it could be once a week who knows - but you might be able to stay on top of it.

On the other hand though if you do use overflows, metal halide lighting etc then probably the aquarium is going to require more water top ups than the aquariums that do not - I know mine does!

On my aquarium I use an automated water top up device. This is controlled by a float valve which is installed into the sump and is hooked up to the reverse osmosis unit. When the float device detects that the water level has dropped in the sump due to evaporation the switch opens and water is allowed to flow through the reverse osmosis unit into the aquarium, therefore doing the water top ups for me.

When I prepare for a water change I lift the float valve out of the water to activate the reverse osmosis unit, move the reverse osmosis feed pipe into the water change bucket and allow it to fill. When it is full I put the feed pipe back into position as well as the float valve.

On my fathers aquarium, however he does does not use overflows and uses fluorescent tubes therefore the water evaporation is very low. He manages to maintain excellent stability in his aquarium and maintains stability of salinity by doing manual water top ups and I have to say that his reef tank has to be one of the best I have seen.

What I like about auto top up device is that the top ups are performed when I am at work, away on holiday and even asleep.

Of course you do not need to rush out and get one. If your aquarium does not require a large amount of water top ups then you will probably be able to maintain it yourself, however if you do experience a large amount of evaporation and have to top up with a large amount of water then possibly one of these devices is for you.

I know that it has worked for me.

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Tags: Aquarium Maintenance, Care, Equipment, reverse-osmosis, Water Quality

Is Yours Scummy?

Sounds as though I’m getting too personal! I’m not, it is definitely to do with the fish only aquarium or reef aquarium. It is equally relevant to both. Another possible target of such a question is the protein skimmer. That could be involved, but not entirely.What I’m actually on about is the aquarium water surface. The best condition for the water surface is clear and clean. This is because this area is a major point for gas exchange.

A scummy water surface can be seen best by looking upwards at it through the front viewing glass. The scum is usually a mixture of bubbles, very small bits of organic matter or general dirt, and has an overall oily appearance. If it is there it most certainly is not wanted.

What causes this surface pollution? First of all, the seawater may hold an excess of dissolved organics. These organics can be generated by overfeeding, excess fish, lack of water changes etc. The organics tend to accumulate generally in the top ½” or so below the surface (this does not take account of powerful water circulation features, but is correct overall). Organics are attracted to an air water interface which is why this occurs. This is how the protein skimmer functions, by presenting a large air/water interface for the organics to ’stick’ to. This air/water interface is, of course, the mass of tiny bubbles within the skimmer chamber.

One method of removing the surface pollution is to use strong absorbent paper sheets, which are laid on the surface gently and then gently removed. Much of the pollution can be removed this way. It is not particularly easy, however, and doesn’t treat the cause, so it is likely that the scum will reappear.

So, if scum has appeared on the water surface, the first thing to check is the protein skimmer. Is it functioning correctly? Is it cleaned regularly (scum accumulation in the skimmer neck will impair the rise of foam towards the collection cup)? Has it the capacity to deal with the water volume? As a general guideline, the skimmer should be rated around twice the capacity of the aquarium system net gallonage.

Having checked this, the next check is feeding. Overfeeding can increase organics (and nitrate/phosphate) so the answer is - don’t overfeed.

Water changes should be completed on a routine regular basis. Not only will this reduce organics, it should reduce nitrate/phosphate to an extent and go some way to replacing trace elements.

Many aquarium systems nowadays will not suffer from surface scum. This is partly to do with vigorous water movement, but also because many systems use weirs or other overflows to deliver water to a sump below the display aquarium. These weirs and other overflows allow the water to flow out of the aquarium at the surface, and thus accumulating debris and organics go with it. The water when in the sump is available to a protein skimmer when organics are removed.

A clean water surface is essential. This is because, as already said, it is a major area for gas exchange. It is where oxygen is taken into the water. Oxygen rich aquarium water will deliver, other things being equal, healthy livestock.

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Tags: Aquarium Filtration, dissolved-organic-compunds, Equipment, Protein Skimmer, Water Quality

Don’t Ruin Your Water By Overfeeding Your Fish

No matter what type of aquarium you keep or are hoping to keep - be this a fish only aquarium, reef tank or mixed reef tank then there is one thing which you need to ensure.

Water quality.

Let’s face it the aquarium is a closed environment. The fish, corals etc have no way to escape. They live, breathe, feed etc in the water which you, the aquarist provides them,

If you take a closer look at the various components (if that’s what you call them) in the water then basically it is like ‘pea soup’. It is a mixture of various nutrients, chemicals etc which all work together to make up the water.

There is a very fine line in the aquarium between good water quality and bad water quality. Of course we all should aim for excellent water quality but at the start let’s aim for good water quality and attempt to improve it from there.

All it takes to tip the balance from good water quality to bad water quality is an inbalance so why assist in this inbalance by feeding the fish to much.

In my opinion it is better to feed the fish little and often, however this is not always possible due to the lives we all lead. Of course there are automated feeding deviced which we can procure and install but in my opinion this is taking some of the enjoyment away. I don’t know about you but I thoroughly enjoy feeding the fish.

So if you can’t feed little and often what do you do.

Well a lot of people come home from work, spend some time with the family and then dump some food into the aquarium and believe that this is ok.

It isn’t unfortunately. Sure the fish will survive but you could inadvertanly be harming the water quality in the aquarium. Fish by their very nature will feed when food becomes available. The trouble is that the fish will not digest all the food which it has eaten. A lot of the food will pass through their body partially digested back into the aquarium where it will slowly rot and deteriorate the quality of the water.

Scavengers if you have enough may assist but more than likely you will start to see climbing nitrates etc.

What I do is feed sparingly throughout the evening. I always soak all food prior to adding it to the aquarium in some aquarium water and then feed a little. I use this time to watch the fish closely to ensure that they are all feeding etc. I then wait an hour or so and then feed them some more. I tend to perform 2 to 3 feeds per evening, however there are nights when I feed less.

Personally I have found that by feeding sparingly that the fish appear to be healthy and I am able to maintain excellent water conditions.

I know that it is hard to not feed the fish as much as it is a very enjoyable time. Plus the fish have a habit of coming to both the front of the aquarium and the waters surface begging for food when they detect your presence. Remember that this does not mean that they are hungry. This is a natural response.

Look at it another way. Would you live in a home which was polluted with gases and other substances. Of course you wouldn’t. You want to live in a home where the air is fresh, free from toxins and will not harm you. Your fish are the same but unfortunately they do not have the benefit of being able to go outside if the water is bad quality.

Basically you are the hand of the fish god. You provide them with food, you care for them but you also have a responsibility to ensure that the habitat which they live in is the best it can be.

Don’t ruin it by overfeeding.

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Tags: home-aquarium, marine-aquarium, marine-fish, saltwater-fish, Water Quality

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