Substrates for the Home Aquaria


Gravel:

Most commonly used.

Size: From Coarse pea gravel to fine as 1 - 2 mm.

Varied colors, from naturally colored or dyed. Can have an epoxy type coating that is safe for the aquarium.

If rough or sharp it isn't suited for bottom dwellers and can cause damage to most fish.


Shell grit, crushed limestone, crushed marble, crushed coral, coral sand = aragonite:

Main component is Calcium Carbonate.

Increases water hardness and Ph.

Good for Salt tanks and African Rift lake cichlids. Can also be good for some inverts like mollusks, snails and corals which use the calcium. Poorly suited for river species which are adapted to soft water.


Peat:

Decomposed plant matter. Commonly used for soft water or black water species. Soft texture also good for cories.

Contains substances that is good for plants and the reproductive health of fish. Helps prevent algae and kill micro-organisms.

Often stains water yellow or brown due to tannins.


Sand:

Examples: Play sand, eco complete, and black onyx sand.

Good for bottom dwellers that like to burrow or sift through the sand, like cories.
Easy to keep clean as everything stays at the top of the sand, so a light hover of the vacuum during water changes does the job.

Can pack down and cause pockets which if left will build up with toxins. Suggested to take a fork or chopsticks and poke into the sand in all areas. Malaysian trumpet snails also helps prevent this.

I use sand and do this monthly.


Latrite:

Weathered Clay from tropical and subtropical areas which has been burned by the sun over thousands of years.

Does not release minerals or nutrients, but can store them for plant use.

Cat litter is the cheapest form of latrite, but must make sure it doesn't contain perfumes or clumping additives.


Fluorite:

An Iron rich stable porous clay gravel

Colors, Brown and Red

Used for naturally planted aquariums. May be mixed with other gravels but does best alone. If mixed the ratio should be 50 x 50%.

Depth of the layer should be 2 inches (5 cm)

When using Fluorite, make sure to add water slowly, Will cause some cloudiness, but will clear within 2 - 12 hours.


The Natural Tank: (Not suggested for beginners)
Low maintenance, no chemical filters. Just use a power head for water movement, with a prefilter for mechanical filtration.

1st layer: Substrate consists of 1 - 1 1/2 inches of an unsterilized top soil or potting soil, with no chemicals added.

2nd layer: 1 - 1 1/2 inches of 2 - 4 mm gravel.

If soil is acidic you can add pelleted dolomite or crushed shells mixed well to gradually raise hardness.

Do not add peat or ferts. You can add decomposed organic matter like compost between the soil and gravel.