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Aquarium substrate calculator
Enter the floor area and the depth you want. You will see how many litres and kilograms of substrate you need and how many bags that is.
How it is calculated
Litres = length × width × average depth ÷ 1000 (all in cm). If the substrate rises towards the back, the average depth counts: 4 cm at the front and 8 cm at the back give 6 cm on average.
Litres become kilograms via the bulk density of the material: gravel about 1.5 kg per litre, sand 1.4, coarse grit 1.6. Aqua soil is light and porous, about 0.65 kg per litre, and is therefore usually sold in litres. Switch the bag size to litres in that case.
Example: 80 × 35 cm, 4 cm at the front, 8 cm at the back: 80 × 35 × 6 ÷ 1000 = 16.8 litres, about 25 kg of gravel.
Which depth is right?
- Planted tank: 4 to 5 cm at the front, 7 to 10 cm at the back. The slope makes the tank look deeper and gives large plants room for their roots.
- No or few plants: 3 to 5 cm is enough.
- With a nutrient base: 1 to 3 cm of nutrient base below, at least 3 cm of gravel or sand on top so nothing is stirred up.
- Bottom sifters such as corydoras or kuhli loaches: fine, rounded sand, at least in one area.
In the app: a shopping list for your tank
The tank planner in Aqualizer puts substrate, plants and equipment on a shopping list that matches size and stocking. Plant suggestions take into account whether animals dig in the substrate.
- Shopping list with amounts
- Plants matched to light and stocking
- Top view for aquascaping
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Aquarium substrate FAQ
How much gravel do I need for my aquarium?
Length × width × depth in cm ÷ 1000 gives the litres, times 1.5 the kilograms. For an 80 × 35 cm tank with an average of 6 cm that is almost 17 litres or about 25 kg.
How deep should the substrate be?
For plants 5 to 8 cm, a little less at the front and more at the back. Without plants 3 to 5 cm is enough.
How much aqua soil do I need?
The same number of litres as for gravel, but soil weighs only about 0.65 kg per litre. As it is sold in litres, switch the bag size in the calculator to litres. Soil settles a little at first, so plan one extra bag.
Gravel or sand?
Both work for plants. Sand is better for animals that sift through the substrate, such as corydoras. Gravel is easier to keep clean because debris sinks between the grains instead of lying on top.
Do I need to rinse substrate first?
Gravel and sand yes, until the water stays clear. Aqua soil no, it would fall apart. The instructions on the pack take precedence.