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

Maintenance Day - Extended

Maintenance day comes once a week when the necessary checks and cleaning are done to keep the display (a soft coral reef) looking at its best. The display is fine during the week, just the slow accumulation of algae on the viewing glass. It only needs a daily top-up to adjust the water level and, of course, the inmates need feeding. Feeding is a real pleasure, the fish have been in for well over five years and nearly talk to me when I’m near. ‘Food, you idiot’ I can almost hear them call.

Anyway, the maintenance. As usual, the glasses were cleaned, no big deal, not a lot of algae. Pumps, skimmer, lights and filters were checked, as was the temperature. No problems.

Having finished, I always make time to look at the display, to appreciate it. It was during this that I noticed a large soft branching coral leaning way over another, and the smaller one had some of its polyps closed. Clearly didn’t like being in contact. Right, thought I, I’ll check the size of the bigger coral. So I carefully bent the bigger coral so I could see the base. The coral now nearly covered the rock it had been ‘planted’ on. As I released the coral the epoxy putty that fixed the rock came away. The rock fell over. ‘Oh dear’ I said…or something like that!

Having brought the packet of epoxy putty from storage in preparation, I studied the position the rock would need to go in so that the bigger coral would not over reach the smaller one. During this my eye was drawn to a solid mass of colour further along the back of the tank. This mass turned out to be ten baby toadstools (Sarcophyton sp). The heads were from about ¾” to 1 ½” in diameter. From above they were a solid mass of polyps. It was obvious that, left alone, there would be problems with growth, eventually affecting two larger toadstools. These ten babies were pruned, this was done by removing the heads. It is likely that at least some of the stalks will form new heads. Having removed these ten, I saw two more lower down (I was a bit surprised - what about the light?). These two also had their heads removed. Sounds like something from the French revolution. There remains a group of three slightly larger toadstools, a bigger one toward the back glass, and one on the left, nearer the front, half way down the reef.

Job done, except I still needed to put the other coral rock back with the epoxy putty. This is an easy job and didn’t take long.

Once again I sat back and viewed the display. Some of the corals were not too pleased at my efforts and were sulking. Not a problem, they’ll soon be out again.

I put away the equipment and additives etc needed for the routine maintenance. Cup of coffee time.

I’m not sure what made me do it, but just before I lowered the lighting array, I ran my eye over the back of the tank from above. Maybe I was hoping to see a baby coral of a different type or something. What I did see was not pleasing.

At first I thought there was only one. Easily recognisable. Not wanted. An aiptasia anemone. Soon sort you out. I have a continuing argument with aiptasia and have fairly regular skirmishes with them. I’d discovered the aiptasia because with the toadstools present it couldn’t be seen.

Out came Joe’s Juice (good old Joe, whoever he is!) and I placed the syringe over the anemone. No problem. The anemone reacted swiftly as usual.

Trouble was, I now realised there were more than one, maybe five or so, but not particularly large, the tallest being around 1″. They were accessible. I’ve learned to be quite sneaky, not throwing a shadow over the anemones or touching them as they may retract. The fluid was applied successfully - the anemones reacted as they should.

The maintenance took twice as long as normal. Still, if I hadn’t done the toadstool pruning…

I’m always on watch for changes in the display and coral problems (usually excess growth).

I just wish the aiptasia could be more useful, like providing food for a reef friendly colourful creature that will most definitely eat them.

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Tags: aquarium, Aquarium Maintenance, Care, home-aquarium, marine-aquarium, reef-tank, saltwater-aquarium

Why Does Sand Become Such A Detritus Trap?

Not all marine aquarium systems use sand. These are said to be ‘bare-bottom‘, and the aquarists have decided to forego a sand bed in the interests of cleanliness. When the aquarium is new, the bare bottom does look unfinished, but in a little time if the seawater conditions are correct the bottom is covered in different algae, and this can look very attractive. Note this is not the often persistent nuisance algae, but decorative types.

I would hazard a guess that the majority of systems have sand in. This can be either decorative sand or a deep sand bed (DSB) or plenum (a raised DSB).

The sand used on a DSB is of fine particles, and dirt that reaches its surface has a tendency to sit there. Eventually it is utilised by the tiny life forms that inhabit the area. Some may penetrate a little way but not a lot and not very far. These beds are around 4″ deep or more.

If the sand is used for decorative purposes only it is placed in the display aquarium and covers the base. The sand is usually coarse and makes a very attractive addition to the aquarium. These beds are often up to 1″ deep.

The reason the sand becomes dirty is mainly because of the size of the grains. In the DSB as stated it is fine, perhaps it could be described as very fine. If a fairly strong water current hits it  a cloud can be raised. Though problems can arise with a DSB, with proper construction and sufficient life it is not usually dirt penetration.

The coarse sand of the decorative sand bed is a different story. Fish faeces, bits of food, dead algae and other general rubbish can fall to the bed. It breaks down and falls between the grains. The grains are coarse enough to allow tiny dirt particles to follow the ’channels’ formed by the spaces between grains. Enough of this dirt can cause the sand to become clogged. This was a major problem with the under gravel filter of yesteryear, which pulled water down through coarse sand and the dirt with it.

With a decorative bed the way to prevent this is to stir the sand frequently with a clean stick. The stirring can be reasonably vigorous and is best done at the time a routine water change is performed. This allows the aquarist to stir the sand and follow the stirring stick with the intake of the water hose, removing dirt. There isn’t any need to do all the sand bed at once, just a proportion at each change. The aquarist can become very expert at this job.

A DSB should never be stirred or the disturbance can spoil the filtration capability of the bed. As said, a well made DSB will possibly look scruffy but should never become really dirty.

It is important to stir a decorative sand bed routinely as described as it prevents the bed from becoming really dirty, which would make the cleaning job much more difficult. If the bed is really very dirty, it would probably be best to siphon out a proportion of the bed at each water change, thoroughly rinse it, and then return it. Routine stirring will prevent the need for drastic cleaning and maintain the attractive appearance of the display aquarium.

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Tags: Aquarium Filtration, Aquarium Maintenance, Care, deep-sand-bed, plenum

Maintain That Skimmer

The protein skimmer is a device that is essential to the maintenance of high quality seawater in nearly all systems. There is a system that claims to not need a skimmer, but aquarists often run one anyway. Using a protein skimmer is particularly useful to experienced aquarists and beginners alike.

The skimmer when purchased, whether a hang-on or stand alone model, should be sized at around twice the net gallonage of the system. This is because manufacturers can be a little enthusiastic about skimmer capabilities, and it also takes into account, up to a point, the less efficient skimmers on the market.

Any device is only as good as the necessary maintenance it receives. The skimmer is no exception.

There are (I assume) not that many air driven skimmers left in use. If the skimmer is air driven, then it is important to ensure that maximum air is being delivered properly. This is done by ensuring that the air pump is operating at full efficiency, without clogged air filters or damaged diaphragms. The bubbles coming from the air ’stone’ should be very large in number and very small in size. If they are not, change the ‘stone’ for a new one. If this doesn’t make any difference check the pump for problems as above.

The skimmer is more than likely to be a venturi model nowadays. These come in different guises that are essentially the same - flowing water from a pump passes an intake where air is taken in. The air is pounded into small bubbles by the pump impellor or a variation of this. Again, the bubbles should be very numerous and very small, If they are not, check the air intake (venturi) as these have a tendency to block. Switching the unit off can often clear them by allowing the blockage to dissolve. If this doesn’t work, check the air line to the venturi is clear. Always adhere to the manufacturer’s maintenance instructions.

There are other skimmers which are less common.

All skimmers should have the bubble chamber packed with bubbles. This is often evident by the colour - the chamber appears close to white.

A very important maintenance task with a skimmer is cleaning. Over time, the period depending on the level of dissolved organics in the seawater, the cup will fill. This should be emptied and cleaned. Whether the cup is full or not, the aquarist should check the condition of the effluent throat (the part where the bubbles rise up towards the cup). This is because a layer of scum builds up here, and the efficiency of the skimmer is directly affected by it. Clean it off and maintain efficiency.

A skimmer does not always perform at full efficiency when new. This is because of the manufacturing process and the plastic. It will soon settle down, however. The same thing could happen for a shorter period when the skimmer has been cleaned.

The great majority of aquarists should have a skimmer and run it continuously. It is a direct contribution to the health of the aquarium.

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Tags: Aquarium Maintenance, Care, Equipment, marine-aquarium, Protein Skimmer

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

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