Substrate Calculator
Calculate how many kilograms or litres of substrate you need.
How it works
Substrate volume (L) = Length (cm) × Width (cm) × desired depth (cm) ÷ 1000. Sand/gravel ≈ 1.5-1.6 kg per litre; aqua-soil ≈ 0.8-1.0 kg per litre. Use 3-5 cm depth for most tanks, deeper for rooted plants.
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Formula & Method
Substrate volume (L) = Length (cm) × Width (cm) × desired depth (cm) ÷ 1000. Sand/gravel ≈ 1.5-1.6 kg per litre; aqua-soil ≈ 0.8-1.0 kg per litre. Use 3-5 cm depth for most tanks, deeper for rooted plants.
Example Calculation
A 60 × 30 cm base at 5 cm depth = 60 × 30 × 5 ÷ 1000 = 9 L of substrate ≈ 14 kg of gravel.
Frequently Asked Questions
How deep should aquarium substrate be?
Two to three centimetres for a lightly planted or bare tank, four to six for a rooted planted tank, and up to ten at the rear for aquascapes using a slope. Deeper than about 10 cm risks anaerobic pockets in fine sand.
How much gravel do I need for my tank?
Multiply length by width by desired depth in centimetres, then divide by 1000 for litres. Gravel weighs roughly 1.5-1.6 kg per litre, so a 16-litre requirement is about 25 kg. Buy 10% extra.
Is sand or gravel better?
Sand is essential for corydoras, kuhli loaches and other sifting fish, whose barbels are eroded by sharp gravel. Gravel is easier to vacuum and less prone to anaerobic pockets. Many planted tanks use aquasoil capped with either.
Do I need to wash new substrate?
Yes for gravel and sand - rinse until the water runs clear or you will cloud the tank for days. Aquasoil should not be washed; rinsing breaks down the granules.