Step By Step Seawater Change

Routine seawater changes are recommended for good reasons, for example minimising nitrate, re-introducing trace elements removed by protein skimming and/or activated carbon, and general freshening up.

The guideline for the amount of seawater to change is 10% of the total system net gallonage. This amount can vary once the aquarist has experience of the system, but routine changes should be done.

So, the seawater change and its preparation then. It is assumed that the aquarist has a seawater safe bucket, dry sea salt, scales, tubes for removing and replacing the seawater (tubes with a diameter of around ¾” (circa 19mm) are best), a heater, and an air pump or powerhead. The heater, air pump or powerhead do not need to be powerful, they are not dealing with a large amount of seawater. There is also a need for a hydrometer.

It is also assumed that the aquarist is aware of the amount in gallons that represents 10% of the system net gallonage.

The best fresh water for use in mixing seawater is reverse osmosis (R/O) and the aquarist will need to ensure that there is sufficient for the mixing process.

First, have a look at the instructions on the sea salt package. It is often stated how much salt is required for a particular gallonage at a particular specific gravity (SG) and temperature.

Routine seawater mixes are going to be made many times in the future so on the first occasion a little extra work is required, which will save time on following mixes.

Using the information from the package, pour an amount of salt on to the scales. Keep it below the suggested amount. Note the amount in a notebook (a notebook is a really good thing to have). Now, pour in sufficient fresh water to reach the required gallonage mark on the bucket. Give the mix an initial stir with a wooden spoon or stick.

Place the heater and powerhead (airstone) into the bucket and plug them in. Put the lid on the bucket and run it for around 8 hours or so (do not seal the lid, drill an air hole if necessary), to ensure the salt is mixed and the temperature is the same as that in the aquarium.

After the requisite period has passed, measure the SG of the seawater. Is it low? If so, add a little more salt, but weigh it on the scales first. Note the weight of the salt with the previous note. Continue with this until the SG is as desired, giving plenty of time for the salt to dissolve, two hours or so. When the required result is achieved, add up the total weight of all the salt used. This is the amount you will need on future occasions. Note the total weight down.

If after the initial period the SG is too high, add small amounts of fresh water until it is correct. When a new mix is to be prepared, reduce the amount of salt used and proceed as above, always keeping a note on salt weight for future use. It is unlikely that the SG will be too high - this is why the salt was reduced from the amount recommended by the manufacturer.

Check the seawater temperature is at the level required. If it isn’t, then the thermostat can be adjusted. Remember that SG is affected by temperature, so check the SG after any temperature adjustment.

The SG and temperature should be the same as those of the aquarium seawater.

Once the process to determine the amount of salt needed per mix is concluded, and the heater brings the temperature to the correct level, future mixes are straightforward.

The appropriate amount of seawater in the aquarium needs to be removed. This is easily achieved with a bucket (separate from the new mix bucket) and a hose. The hose needs to be long enough to reach well into the bucket when the other end is at the bottom of the aquarium.

When seawater is being removed it is a good opportunity to siphon out any debris that is seen. To make this easier by better control of the tube, the aquarist can bind the end of the tube to a length of wood which is stiff but not too wide. The wood can be around 12 to 18″ (circa 305mm to 457mm) long, depending on the depth of the aquarium and the aquarist’s needs.

Place the tube with the wood into the aquarium, then give a good suck on the other end and place that end in the bucket. Seawater will flow through the tube into the bucket. A little practice makes the ’suck’ period easy.

If any debris is noticed it is easily removed so long as the seawater is flowing.

Watch the amount of seawater that is removed and when it has reached the relevant mark on the bucket, remove the wood end from the aquarium to stop the flow. This seawater can be discarded.

Putting the new seawater into the aquarium is really easy. If the aquarium is near some stairs, put the new seawater bucket on the stairs and trail a tube down to the aquarium. It may be necessary to have a different tube for this. It is best if someone can ensure that the tube does not come out of the bucket. At the aquarium end, another one of those technical ’sucks’ will start the seawater flow into the aquarium, Once the bucket is empty the flow will of course cease.

If the aquarium is not near stairs, no matter. The aquarist can use a powerhead (use the one in the new mix) and a suitable diameter tube, and pump the seawater in. The powerhead will not remove all of the seawater, the last bit can be put in with a small jug.

All that remains is to check the SG of the aquarium seawater (with the new seawater in) to ensure all is well. If the SG is a little low, just increase the amount of salt a little on the next new seawater mix. Likewise, if it is a little high decrease the amount.

All that remains is to dry the new seawater bucket and store it until the next time, along with its heater and powerhead or air pump.

One note - when removing the heater from a new seawater mix be sure the heater is cool. If it is not and is out of the water, then the glass could crack.

For the first two or three new seawater mixes check that the SG is as desired, and do an occasional check after this. SG checks of the aquarium seawater itself should be done routinely

Routine seawater changes are simple and quite quick if the above suggestions are followed. Anything that simplifies routine maintenance and gives more time for watching the aquarium can’t be bad.

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Tags: Aquarium Maintenance, Aquarium Water, Care, reverse-osmosis, Water Quality, water-testing

Why You Should Use Reverse Osmosis Water

Fresh water is used constantly by the marine aquarist, first when the aquarium is initially filled and then for ongoing routine water changes. Of course, an appropriate amount of dry salt mix is added. Fresh water is also used for evaporation top-ups.

On the face of it using tap water seems reasonable - but is it?

Tap water is prepared for human use, and is safe: children and adults use it for drinking, cleaning teeth, showering etc. There are regulations about the minimum condition the tap water should be in, and the water authorities adhere to this. But…

Tap water has levels of nitrate, phosphate, insecticides, heavy metals, chlorine, chloramines etc that the marine aquarist could well do without. In other words, tap water isn’t just pure water. The unwanted parts vary according to area. Some agricultural areas could have higher nitrate and insecticides etc, and other areas could well have higher levels of heavy metals and the like. Water companies tend to add chlorine and chloramines as a matter of course.

Seawater quality is very important in a reef system and also in a fish only system. By using tap water the aquarist is adding items that are known to be a potential problem - nitrate is an obvious example. There is a method that is easy to use and solves the ‘contamination’ problem easily.

This is the reverse osmosis (R/O) method. This is were a filter, the R/O unit, is connected to the tap water supply, the tap water slowly flows through the filter, and the purified water is collected in a bucket. It really is as simple as that.

Reverse osmosis filters come in a range of sizes, with varying outputs. The output is often given as gallons per day, and the aquarist needs to choose one that will produce enough water for a routine water change (the initial fill of the aquarium is usually ignored as this will normally only be done once. R/O water should be used though).

The filter has stages, and the first is normally anti-sediment, which protects the later stages from clogging. Then comes an activated carbon stage, where chlorine is removed from the water. This removal is important as chlorine degrades and eventually could spoil the R/O membrane. The R/O membrane is the final stage- the membrane is very fine, measured in microns, and will only allow pure water to pass. Once the water has gone through these three stages it will usually be 95 to 98% pure.

Some R/O filters have a fourth stage, where the purified water goes through a special granular mixture. This gives the water a final clean. The fourth stage is not essential, but it does further increase the purity of the water.

Not all the tap water that reaches the filter will be purified, about one part in five is. There is some small variation on this. The water that gets to the storage bucket is ready for use, but the other four fifths or so is discarded along with unwanted contaminants. This latter water could be collected for use in a garden or similar if wanted.

The purified water that is in the collection bucket is ready for salt to be added to prepare a routine water change, or for use as a top-up to replace aquarium evaporated water.

There is a further reason why R/O water should be used, and that is to do with the dry salt that most aquarists use. Commercial salts nowadays are of a very high standard because the manufacturers make every effort to produce a properly balanced mix without contaminants. In fact, many manufacturers trumpet this fact by adding wording to the salt pack such as ’No Nitrates, No Phosphates’ or similar. So why add contaminants by using tap water and negate, even partially, the purity of the salt?

R/O filters do not cost a lot and are readily available. All they require is a tap water supply and normal mains pressure. The manufacturer’s advice on maintenance, which doesn’t amount to much, should be followed.

By using R/O water the aquarist is ensuring as far as possible that the water that is put in the aquarium is of the highest quality, and it is highly recommended.

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

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

Testing Synthetic Seawater Against Natural Seawater

A couple of recent comments from users of natural seawater (NSW) started some questions in my mind. One question led to another and I ended up trying to think up a reasonably accurate way of proving the best. With NSW the question of potential pollution and the need for transportation and storage is ignored.

The heading may on first thoughts seem strange. Mother Nature provides the seawater on the wild reefs, and that is where the majority of our livestock comes from. So it follows that NSW must be best. Yes it does and it is - on the wild reef. It may well be best in the aquarium as well. However, in the natural world the seawater has, to all intents and purposes, an inexhaustible supply of, for example, calcium. Huge amounts of seawater are available and this washes the reef. All the other seawater contents are available in the same way.

In the aquarium the amount of seawater is obviously restricted. Therefore, even if the NSW was perfect to start with the demands of a hard coral captive reef would deplete some of the constituents, again for example calcium. This is why so many aquarists use additives, or calcium reactors and the like.

Synthetic salt mixes are of a very high quality nowadays. They don’t fully equate to NSW, as, to my knowledge anyway, there isn’t a manufacturer who can create a salt to that accuracy. Because of the demand for the example calcium in an aquarium, some manufacturers boost this. Nevertheless, aquarists usually need to supplement to maintain desired levels. In addition, many aquarists maintain a higher alkalinity level to resist the higher acidic pressure within the closed aquarium.

So in my mind NSW is best, I have no doubt, at least to start with. But what of ongoing use, what then? How could it be shown one way or another?

I suppose the only way to show any difference in the ongoing use of the two types of seawater would be to use them both at the same time. A great deal of care and discipline would be needed. I am not a scientist and have not had any scientific advice, but if such advice were forthcoming it would no doubt be that in any trial all possibilities of unwanted influence must be removed. Otherwise at the end of the trial arguments could be made that X caused this in NSW but was not available to synthetic, and so forth.

So the trial would be something like this. A scientist might well find holes, but here goes anyway.

Two equally sized aquariums (they wouldn’t need to be very large) would be obtained. Sumps would not be necessary. A reef would be built in each aquarium, but not out of any type of rock. Rocks are too variable in size, shape and weight. Therefore a structure, exactly the same in each aquarium, would be built to support any corals. This would equalize gallonage in each system and hopefully circulation.

Remembering that this is a trial to show which seawater is best for livestock, equipment would be fitted to maintain water quality. An efficient protein skimmer of the same make and model would be fitted to each aquarium. So would heaters of the same wattage, to maintain each system at the same temperature. The lighting system, metal halides probably, would light each and be exactly the same make of bulb, the same power and spectrum. Circulation devices would be the same make, model and power. Additives for the example calcium would be available from the same manufacturer so that the amounts being added could be recorded during the trial. Any other additives would also have the amount recorded. When additives were used, each system would be kept at the same level.

The equipment mentioned above would be fitted inside each aquarium in the same place. The lights would be the same distance from the water surface.

The two aquariums would need two logs, so that they could be compared at the end of the trial. These logs would cover at least weekly tests on the same day of all the normal reef aquarium parameters checked for. Temperature would need to be recorded also.

Evaporation would be physically topped up with reverse osmosis (R/O) water from the same R/O filter, always ensuring that the level ended up correct. I assume there would be no point in recording the amounts required for these top-ups.

Then we come to the standard practice of routine water changes. In a trial such as this, normal practices would need to be followed. So each week 10% (or whatever agreed percentage) would be changed, NSW for NSW and synthetic for synthetic (using the same make of salt as used at the fill of the aquarium).

Then there is stocking - an aquarium without livestock is not going to prove much. Perhaps there would be a cleaner shrimp or two in each aquarium. Fish would be introduced to the full recommended level for a captive reef system. The fish in each aquarium would be the same, as far as possible the same size. Corals are more difficult, but again each aquarium would be as far as possible fully stocked with the same type and size of coral (not so ‘easy‘).

Feeding would of course need to be sufficient for the proper nutrition of the livestock. The food that entered each system would be measured by weight and of the same type at the same time. The food would be from the same source and/or manufacturer.

Routine maintenance in addition to water changes would be the same and thorough on each aquarium - skimmer cleaning etc.

At the end of the trial period each aquarium log would show a history of the coral growth and colour, fish health and any particular livestock points of note. The tendency of the seawater would have been recorded over time for each aquarium, and would indicate calcium demand, nitrate build up, pH, alkalinity changes etc.

Out of this attempt to run an unbiased trial, it would be the livestock that would be paramount. The livestock would be the judge and jury. If one reef was clearly better than the other then there would be the answer. Also available would be the information about how much additives had been needed in each system, giving an indication of cost (on top of lighting, heating etc).

Then aquarists would know which is the better for a captive environment. The unbiased trial figures would be there to see.

Mind you, in scientific circles there always seems to be argument about any trial. If the result favoured NSW, synthetic salt manufacturers would claim it was because their particular salt had not been used. But the above, to my untrained mind, seems reasonable.

What do I think would be the result of such a trial? As an out and out guess, I would say they would be more or less equal. I have always believed that NSW is the best - but seawater degrades/changes in a captive system. I think it was Dr Ron Shimek who stated that systems he had tested ‘bore no relation’ to real sea water. So synthetic or natural, they would both need supplementing after a time with a percentage of new seawater plus additives.

There are two questions that remain though that - just maybe - could tip the result. The first is that newly mixed synthetic seawater is ‘harsh’ and dead even though it has been mixed for hours in a bucket. NSW is, well, natural, more ‘pleasant’ perhaps for the livestock. Would that make a difference? The second is that NSW is ‘alive’ - is there something there that would make the difference, something synthetic doesn‘t have?

Professional testing as above is not going to happen. The synthetic salt manufacturers have no interest for obvious reasons, and the scientific community has no interest from the ‘what to use?’ point of view.

Transportation and storage are obvious concerns for the use of NSW (disregarding potential pollution). Most hobbyists are happy with their captive reefs and the use of synthetic salts. Some of the photographs of these systems show what can be achieved.

Is there an aquarist who has the money, space, knowledge and discipline to have a go? I’m sure there’ll be silence, as aquarists enjoy the hobby, achieve for the most part success, and haven’t the desire to go ’scientific‘.

Wouldn’t it be great though, if an aquarist stated That’s been done, here’s the records. The result was clearly…..!

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Tags: aquarium, Aquarium Water, natural seawater, reverse-osmosis, saltwater, saltwater-aquarium

Do You Have To Use Reverse Osmosis Water?

Reverse osmosis (R/O) water seems to pop up very regularly in questions and discussions. Some aquarists consider the R/O filter to be another piece of equipment that is not really necessary. There is quite a bit of confusion particularly with beginners, which is understandable when the whole spectrum of equipment and guidelines for keeping marine systems is considered.

The heading question can be answered straightaway - no, you don’t. If you’re lucky, and have a water source such as a well that provides water of high purity, or live in an area where tap water is of a really high standard and not polluted with nitrates, insecticides, metals, bacteria (I won’t go on) then the tank seawater mix could well be of high quality.

Some aquarists have tried using bottled spring water and found that the purity was in fact not as thought and/or the cost was prohibitive. Similarly, some have obtained a supply of distilled water from a chemist or other source and tried that. This proved to be an inefficient way of obtaining the amounts of seawater - multiple gallons - often required, plus the cost.

A few other aquarists have turned to Mother Nature, a fine choice provided the transportation and storage needs can be met, and an unpolluted source can be found.

So for the majority it is the household tap. The water from the mains tap is purified and regulations exist for the amounts of pollutants that are acceptable. Nitrate can be present in a surprisingly high amount, as can phosphate, plus the insecticides etc mentioned earlier.

The water from the tap at the very least should be tested for nitrates and phosphates before consideration is given to using it for a salt mix. If tests are not done then the aquarist is possibly preparing a potential home for nuisance algae, particularly if high power lighting is being used. Added to the pollutants in the tap water are the natural developments in the tank because of the natural processes of the livestock, and the results of potential overfeeding.

Personally, I find it difficult to follow the logic (should I say illogic) of not using R/O water. First, look at the expense the aquarist has accepted in preparing the aquarium system, having purchased lights, salt mix, test kits, a protein skimmer, canister filter, heater(s), circulation pumps, maybe a calcium reactor etc, and also of course the aquarium and stand. Then there is the internal decoration, such as live rock and maybe sand. The fish and corals haven’t been mentioned yet! Whether a fish only or reef system, it all represents a fair sized investment.

Over and over emphasis is placed on the need for high quality water. To this end, the dry salt mix that most aquarists use is manufactured to a high purity, lacking in such unwanted substances as nitrate and phosphate. Why add less than ideal water to it?

If there is a marine retailer close by, R/O water may be available to purchase by the gallon. Quite reasonably, the retailer has to make a profit. Moving the water in containers is not the easiest practice.

If the aquarist purchased an R/O filter then production of purified water would be straightforward and predictable demand easily met. The cost of the filter, particularly when the cost of other items of equipment is considered, is reasonable.

R/O water is generally 95 to 98% pure and the environment for the aquarium livestock would be enhanced, which is probably the most important point, and the possible appearance of undesirable headache algae would be reduced.

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

How Does Reverse Osmosis Work?

As is so often repeated, high water quality is needed in a marine aquarium. Reef systems need higher quality than fish only, but both need to be maintained at the highest level possible. This is done by regular monitoring of water parameters.

A good way of enhancing water quality is by preparing the routine water change mix (and the initial fill) with a high grade salt mixed into reverse osmosis (R/O) water. This water is obtained by filtering tap water to remove undesirables therefore increasing the water quality in the first place.

R/O devices usually come in a unit containing three pods: there is a pre-filter to remove larger debris, a carbon filter to remove chlorine, and the R/O membrane itself. Some units have a fourth pod, which hold resins that take out any remaining undesirables. There isn’t any harm in having a fourth pod, they will increase the water cleanliness somewhat,  but they are not strictly necessary.

The R/O unit is connected to the mains supply in a convenient out of the way place (simple connectors are normally supplied with the device). The water is driven through the unit by the mains water pressure. They will not work if, say, supply water is gravity fed.

The water first meets the sediment pre-filter, which, as said, removes larger particles so that the next filter doesn’t clog.

Next in line is a carbon filter. This is very important as it removes chlorine. Chlorine is very detrimental to the R/O membrane.

The water now reaches the main point of the exercise, the R/O filter. This is a semi-permeable membrane. In other words, it will allow water to pass but not other unwanted substances. These substances could be insecticides, viruses, spores of fungi, metals, bacteria etc.

Finally, if the device has four pods, the final filter is a ’polishing’ unit. As said, it contains resins which will take out further pollution giving a slightly higher purity.

As has been said, the R/O membrane will only allow nearly pure water to pass through. Therefore there are two water outlets, one for the purified water (known as permeate) and one for the waste (known as concentrate). The aquarist runs the permeate outlet into a container for storage, and the concentrate to a convenient point for disposal.

R/O units come in various ’gallons per day’ outlets. The aquarist should purchase one that will provide sufficient water for the routine water change in a reasonable time. This will cover daily top-ups as well.

It is possible to connect an R/O unit to an automatic top-up device. This means when the water level falls it will be filled with purified water in the absence of the aquarist. For smaller systems, a daily top-up is usually sufficient.

It is very important to follow the manufacturer’s instructions when using the R/O device. The sediment pre-filter should be replaced or cleaned at the appropriate time. It is essential to replace the carbon filter when required, as failure to do so could allow chlorine to reach the R/O membrane and cause damage. This could allow impure water to pass through the membrane. This would mean obtaining a new membrane, which will be in the region of half the price of the entire unit.

R/O devices will provide 1/5th of pure water in relation to the water input. In other words, for every 5 parts of tap water, 1 part of purified water will be obtained. The purity on a three pod system is usually between 95 to 98%.

Using R/O water is highly recommended. As already stated, it sets the seawater quality at a high level from the start. From a logical point of view, manufacturer’s of dry salt mixes provide salt of a very high standard nowadays, with nothing undesirable present, such as nitrate and phosphate. Why pollute this salt with tap water?

If the aquarist has been using tap water to date, changing to R/O water is a good idea. Better, use it from the very start.

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Tags: aquarium, Aquarium Water, Equipment, reverse-osmosis, saltwater-aquarium, Water Quality

Consider Using An Auto Top Up Device

It always surprises me how much water actually evaporates from a [tag-tec]saltwater aquarium[/tag-tec]. 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 [tag-ice]specific gravity[/tag-ice] 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 [tag-self]reef tank[/tag-self] 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

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