Furnishing The Aquarium

You’ve bought your aquarium, now what to put in it?  To achieve a truly stunning aquarium, as well as provide the best possible home for the freshwater tropical fish, consider the following:


The choice of gravel is very important.  If the gravel is too coarse, food will quickly fall beyond the reach of the fish, and will decay, beginning a pollution risk, and if biological filtration is used coarse gravel will not provide enough surface area for the bacteria to colonise, and the water flow through the gravel will be too fast.  If the gravel is too fine, it will pack down too tightly, which will mean that the plants will have difficulty penetrating the gravel, and the water flow rate through a biological filter will be severely impeded.  A medium-sized gravel is best, and a particle size of 0.125″ (3mm) is ideal.

Consider also which fish you will have in the aquarium, and what kind of water suits them best.  If you have an aquarium where the fish prefer soft water, do not use gravel which includes fragments of calcium-rich seashells, as over time this will harden the water.  Some aquarists stock lime-free gravel, so you may want to consider purchasing this.

What about the colour of the gravel?  If a light-coloured gravel is used the aquarium lights will reflect off it, and the fish will appear washed-out, so usually a dark coloured gravel will look best.  It is also possible to buy coloured gravel, and this may look striking, but you will not achieve a natural-looking aquarium.

The amount of gravel required may well surprise you.  To cover a biological filtration system, and give the aquarium plants sufficient gravel to be able to root, a depth of at least 2-3” (5-7.5cm) is needed.  In practical terms this means approximately a 2 gallon (7.6 litre) bucketful for every 1ft2(900cm2) of aquarium floor area.


The most important consideration when choosing rocks for an aquarium is the effect they will have on the water’s chemical composition.  Rocks that are at all soluble, particularly those with any calcium in, will made the water in the aquarium go hard, so do not use unless this suits the fishes requirements.  Examples of suitable rocks for aquarium use are granite, basalt, quartz and slate.  Ensure there are no sharp edges on the rocks where the fish might hurt themselves, and especially do not add coral to an aquarium containing freshwater tropical fish.

Other Decorations

Wood is a favourite for furnishing an aquarium, a strategically placed log or twisted root can add a lot to the look of an aquarium.  Such material can be collected from rivers, marshes and forests, but it must be long dead, with no traces of rotting. This wood will need to be boiled in several changes of water and immersed in water for several weeks until completely waterlogged.  Alternatively dead wood can be sealed with several layers of polyurethane varnish.  Some aquarium stockists will sell wood which is ready for aquarium use.

Another suitable natural material is cork bark, the colour looks good in an aquarium, and it is easy to cut to shape.  Also, plant pots could be placed in an aquarium to provide hiding places, clown loaches in particular would appreciate these.

Most aquarium stockists will also have a range of artificial plants and rocks, and these can look quite effective, and after a few weeks it can be hard to tell them from the real thing.  There are usually also items like shipwrecks and divers, which you may want to consider in the aquarium, but the natural look will then be lost.

Just Tropical Fish is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com. You will not pay any more, and it helps support our site.