Sand – Decorative In The Aquarium?

Sand - Decorative In The Aquarium?

Sand – many new marine aquarists see it as an essential and obvious requirement for the aquarium. It’s very often sold in shops so it must be a requirement? It should be said that some aquariums that have sand look really good as they are properly maintained.

If sand is to be used how should it be used? Seems a strange question, it goes on the bottom so it looks good! However nothing is as simple as that. Most aquariums, fish only or reef, have rocks installed and that is the first checkpoint. The sand should never be placed on the bottom then the rocks placed on top as this will cause rock instability. The rocks should be placed first and the sand put around them. That’s about it then, all done, no problem, next job.

Hold on though, it can’t be as simple as that can it? The answer of course is no, it can’t. The reason why is mainly maintenance and cleanliness. The sand looks great when it first goes in, but will it stay like that – no.

Sand is made of grains which can vary in diameter. Sand that is destined for the bottom of a marine system can be bought in a bag with the correct grain size and fully cleaned, this pre-cleaning is important as there must not be any bits of metal or other detritus present. Even though it is initially clean, when the aquarium is in use over time the sand will get a thin layer of algae on it which is not a problem but could detract from appearance. Also tiny bits of detritus will slowly find their way down through the grains changing the sand colour. This can be combatted by routine cleaning, which can be done using a siphon and a prepared ‘sand head’ which churns the sand about taking the detritus out. This operation takes place when a partial seawater change is done. If there isn’t the time to do the whole bed, it’s done in sections at different seawater changes. It helps if the bed is generally not more than about 1″ (circa 25mm) deep.

This cleaning system falls down though if the sand has been placed all over the aquarium base, around the rocks. How is it accessed? The simple answer is it can’t be apart from one or two areas that could be visible. So what has been created is a dirt collection system over a large part of the aquarium bottom.

The sand around the rocks problem can be overcome by placing a siliconed plastic barrier around the base creating an expanse of sand close to the rocks and up to the glass. The rocks can rest in places on top of this barrier and overlapping a little, thus hiding it. This leaves a clear glass bottom in the hidden places but allows for the aquarist’s desire for sand. This sand still needs to be cleaned of course and care needs to be taken to avoid moving sand over the barrier towards the rocks.

This could sound like an unwelcome increase in maintenance, cleaning the sand. Welcome or unwelcome is a matter for the individual aquarist of course. Many aquarists dispense with decorative sand altogether and save themselves the need to build barriers and carry out ongoing sand cleaning. This is easily done.

The rocks that create the reef are carefully placed not too far from the viewing glass sides leaving only a small amount of uncovered base glass. Care needs to be taken that there is sufficient gap for any small corals etc that are required lower and near the edges. Also there needs to be space for any tools that are used in maintenance operations, such as algae scrapers for the glass, tongs, siphons etc. It is unlikely that any rock would come close enough to the glass to cause trouble with that. The reef after all should look like a reef not a manufactured wall.

When there isn’t any sand on the visible aquarium base, at first it will look strange. However, over a period of time organisms will attach to the base and the unnatural sight will reduce and disappear.

The best method and the one that I used is the plastic sand barrier one. The sand is reasonably easily cleaned. The rocks that overlap the barrier in places hide the plastic and over time the plastic discolours and it eventually disappears. However, I did siphon out the sand eventually as organisms were showing, these organisms eventually covered the sandless bottom and made it look very natural, more natural than the sand. A super result: good looking and a reduction in maintenance as well.


  1. Just read your article. I am an aquarium lover and I recently bought an aquarium. I have been busy buying the different aquarium accessories and recently bought a canister filter. Now I am checking all the websites regarding how to decorate an aquarium. Thanks for your suggestion that sand should not be placed on the bottom. It should be placed around the rocks.

  2. Glad you found help in the article. Sand if desired obviously goes on the bottom but not with rocks on it as they are likely to be unstable. Enjoy your aquarium.

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