Buying substrate for a new bioactive enclosure is where most keepers either run short halfway through the build or end up with three extra bags in the closet. This guide shows you exactly how to work out how much drainage, soil and leaf litter you need, with ready-made numbers for the most common enclosure sizes sold in Canada.
The quick answer
For most tropical builds, plan on 5 cm (2 in) of drainage, 10 cm (4 in) of bioactive soil and a loose 2–5 cm layer of leaf litter on top. Arid and invertebrate builds usually skip the drainage layer and use a deeper 12 cm (5 in) of soil so animals can dig and burrows hold their shape.
The formula
Substrate is sold by volume, so you only need three measurements:
Litres = length (cm) × depth front-to-back (cm) × layer height (cm) ÷ 1000
Working in inches? Multiply each measurement by 2.54 first. Then add about 10% to your soil number, because ABG-style mixes settle once they're watered in.
How much substrate for common enclosure sizes
| Enclosure footprint | Drainage (5 cm) | Tropical soil (10 cm + 10%) | Arid / invert soil (12 cm + 10%) |
|---|---|---|---|
| 30 × 30 cm (12 × 12 in) | 4.5 L | 10 L | 12 L |
| 45 × 45 cm (18 × 18 in) | 10 L | 22 L | 27 L |
| 60 × 45 cm (24 × 18 in) | 13.5 L | 30 L | 36 L |
| 90 × 45 cm (36 × 18 in) | 20 L | 45 L | 53 L |
| 120 × 60 cm (4 × 2 ft) | 36 L | 79 L | 95 L |
| 180 × 60 cm (6 × 2 ft) | 54 L | 119 L | 143 L |
Hardscape, hides and large plant root balls take up space, so builds with lots of rock or wood can usually get by with a little less.
Layer 1: drainage
A drainage layer keeps the soil from sitting in water, which is what makes a tropical enclosure smell sour. Clay bio balls are the easiest option: rinse them, pour in 3–5 cm, then cover with a mesh barrier so soil doesn't wash down. Desert and tarantula builds that are kept mostly dry can skip this layer.
Layer 2: bioactive soil
This is where plants root and your clean-up crew lives. Match the mix to your animal:
- ABG Terrarium Mix for crested geckos, gargoyle geckos, dart frogs and tree frogs.
- ABG Semi-Arid Blend for leopard geckos, bearded dragons and other desert species.
- ABG Tarantula Mix for tarantulas, scorpions and burrowing inverts.
Our mixes come in 3 L, 9 L and 20 L bags. For a 45 × 45 cm tropical build that needs about 22 L, one 20 L bag plus one 3 L bag is cheaper than buying two 20 L bags.
Layer 3: leaf litter and moss
Leaf litter feeds isopods and springtails and keeps humidity up at ground level. One pack of oak or magnolia leaves covers roughly a 45 × 45 cm floor; plan one extra pack for each additional 45 cm of length. In tropical builds, a handful of sphagnum moss in the humid hide finishes things off.
Common mistakes
- Measuring the outside of the tank. Use the inside floor dimensions, especially for wooden or PVC enclosures with thick walls.
- Forgetting slopes. If you're building a hill at the back, measure that section separately at its deepest point.
- Going too shallow. Under about 7 cm, plant roots and isopods struggle and the soil dries out fast.
Shipping substrate in Canada
Bagged substrate is heavy, which is why ordering from US stores often means paying more for shipping and duties than for the soil itself. Every One Bioactive order ships from Ontario, priced in Canadian dollars, with no border fees.
Ready to build? Shop bioactive soil mixes or browse all bioactive supplies.