Find out how much aquasoil, sand or gravel to buy before you start a scape. Enter your tank footprint and the depth you want at the front and back, and the calculator gives the volume, weight and number of bags, with an optional cap layer and a little extra for terraces.
How it works
- Volume = length × width × average depth, where the average is halfway between the front and back depths of your slope.
- Weight uses typical densities: about 0.9 kg per litre for aquasoil, 1.5 for sand and 1.6 for gravel. Check your bag, as brands vary.
- Bags: divide by the bag size in litres or by weight, then round up. The extra % covers terraces, spills and settling.
How deep should substrate be?
Planted tanks usually run about 3–4 cm (1–1.5 in) at the front glass and 6–8 cm (2.5–3 in) at the back, giving roots room and the scape depth. Sand-only tanks without rooted plants can be much shallower. Very deep beds should be built on a sloped base or terraces.
A worked example
A 24 × 12 inch footprint sloped from 1.5 inches at the front to 3 inches at the back needs about 10.6 L of aquasoil, around 9.6 kg. With 10% extra, that is two 9 L bags.
Ideas to scape with it
These calculators use standard formulas and common aquarium guidelines. Fish, plants and rooms vary, so treat the results as a starting point and watch your tank.
Frequently asked questions
How much substrate do I need for a 20 gallon tank?
For a 20 gallon long (30 × 12 in) at an average of 2 inches deep you need about 12 L, around 18 kg (40 lb) of sand or 11 kg of aquasoil. The calculator works it out for your exact footprint and slope.
How deep should aquasoil be?
About 3–4 cm at the front and 6–8 cm at the back is a good starting point for most planted tanks.
Can I put sand on top of aquasoil?
Yes, as a thin cap or in the foreground only. Use the cap layer option to add it, and keep it thin so plant roots can still reach the soil.
Should I rinse my substrate?
Rinse sand and gravel until the water runs clear. Most aquasoils should not be rinsed, as it breaks the granules down; follow the instructions on the bag.
Is my information stored?
No. Everything is calculated in your browser, and nothing you type is saved or sent anywhere. The share link keeps your numbers in the part of the web address after the # sign, which browsers do not send to the website.