Natural Seawater - Is It Recommended?

Mother Nature provides the habitat for the livestock that we aquarists keep in our fish only aquariums or reef aquariums, and this, of course, is the wild reef. Mother Nature is also the provider of the other obvious essential, and that is seawater.

Having written the above it would seem absolutely wrong to state that natural seawater is not recommended. So it would be - natural seawater is recommended.

However, is it recommended overall, for the majority of aquarists? This needs a bit more care, and two questions arise. These are first, the ability to collect the seawater, and, second, before any attempt is made to collect it, what is the seawater’s condition?

Not all aquarists live within easy travelling distance from the sea, but there are a fair number where it could be a viable proposition. So in this case the first consideration is practicality.

Seawater is heavy, it ways somewhere towards 10lbs per gallon. So to do, say, a 10% water change a good few gallons are required. Not so many for a nano aquarium, but increasingly more as the aquarium gets larger. Also of course, some aquarists do water changes that are more than 10%.

This water has to be moved from the sea to the aquarist’s home. This means there needs to be sufficient containers of seawater safe construction which are also strong enough for the journey. In addition there must be transport that is robust enough, and roomy enough, to carry the full containers.

If the aquarist cannot meet these requirements then the obvious answer is to use one of the available commercial dry salt mixes. Transportation problems for these mixes are zero as they come in different size packs, can be transported by car, or can even be delivered to the aquarist’s home.

If the aquarist can meet the transportation need, then another consideration arises. This concerns the question of pollution. It is very unfortunate that many coastal areas are polluted with industrial waste and/or agricultural run-off and the like. The aquarist must be absolutely sure that the seawater being collected is clean. There might be a facility nearby who could advise on this matter. If not, it is better to play safe and use a dry salt mix.

If the coastal water is polluted, then natural seawater could still be used. By going considerably offshore, it is possible or maybe probable that the seawater will be unpolluted - but not definitely so. Again, the aquarist must be certain of the condition.

Going offshore brings the transportation problem back. Is there a boat available? If the aquarist is also a yachtsman all is well and good. If not, the only means is to hire assistance, and then cost is creeping in. In the latter case, the effort may not be financially worthwhile, so again a dry salt mix could be the preferred option.

Using natural seawater brings up another possibility, and that is disease or the introduction of unwanted life. This applies particularly if the natural seawater being obtained is warm.

This danger can be minimised. The collected seawater can be kept in the containers in the dark for a week or better two, and at the same time have it passing through UV (ultraviolet) lamps. These can be obtained specifically for aquarium use. If there were more than one container, they would have to be connected or the aquarist would need more than one UV lamp. After the mentioned period, the seawater could be used after where necessary being heated to the required temperature, and after any sediment that had accumulated on the bottom of the container(s) had been siphoned out.

There is one more consideration. This is that the seawater could still need supplementation. Just because the seawater is natural does not mean that in a reef aquarium there will not be a need for calcium addition and the like. In the confines of the aquarium, a heavy demand will have the same effect as it would if synthetic seawater were in use.

Some aquarists have reported that using natural seawater has a wonderful impact on their captive reefs. This is of course anecdotal but there isn’t any reason not to accept the reports. Perhaps there is some ‘magic’ in natural seawater that makes a difference?

Looking at so many captive reefs that use commercial salt and can be viewed on the internet and in reality, and considering the great success and beauty of these reefs, there isn’t any real need to doubt modern commercial dry salt mixes.

If the aquarist can meet the demands for using natural seawater, then all is well. Most aquarists will be happy using commercial salts.

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Tags: Aquarium Maintenance, Aquarium Water, Care, saltwater, seawater, water changes

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

What Is Displacement

Unless I’m mistaken, it was a Greek called Archimedes who was having a bath one day. He filled the bath full, as the story goes, and climbed in. Of course, the bathwater overflowed. Archimedes puzzled a moment then, realizing what had happened, shouted ‘Eureka!’ and ran out naked. He had discovered displacement.
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Tags: aquarium, displacement, reef-tank, saltwater, saltwater-aquarium

Competition : Name Our Newsletter

Every month we publish a newsletter to all of our subscribers.

This newsletter covers various aspects from our personal aquariums, tips, advice, news and more. We are always on the lookout for information which we can provide.

Of course we also provide information on this site which we hope is beneficial to you.

The newsletter which we provide is a joint newsletter between Aquarists Online website and the Salt Water Aquarium website, however that is where we have a dilemma:

What in the world do we call it? [Read more]

Tags: aquarist, aquarium, AQUARIUMS, reef, saltwater

Performing a water change

Looking around on You Tube I found a video about performing a water change.

It’s quite a well done video, very well put together. There are a few things that I think should have been included in it for example the water is just poured into a bucket and is not heated up to temperature first. Of course you can perform a water change with cold water if you have a [tag-tec]large aquarium[/tag-tec] but if you have a [tag-tec]micro fish tank [/tag-tec]or [tag-tec]micro reef tank[/tag-tec] then I would not recommend it.

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Tags: AQUARIUMS, mix-saltwater, saltwater, water-change