Tank Setup
Substrate
Liters and bag count from footprint × depth (sand, gravel, aquasoil).
For a scaped slope, enter the average depth (front + back) ÷ 2. Buy an extra bag if you slope steeply or fill hardscape gaps.
Results
Volume
25.6L
Volume
6.8gal
Approx. weight
28.1kg
Bags to buy
4× ~9 kg
Planted aquasoil: 2–3" in the front rising to 3–4" in the back looks natural and holds roots. Rinse gently if the brand recommends it.
How to use this
- Measure the interior length and width of the tank footprint (not the outer glass).
- Choose substrate type — density affects how many bags you need for the same depth.
- Set average depth. Planted tanks often use 2–3" front / 3–4" rear; shrimp tanks may stay shallower.
- Order the suggested bag count plus one spare if your hardscape eats volume.
Volume math
- in³ = length × width × depth
- liters = in³ × 0.016387
- bags ≈ ceil(liters × density ÷ bag kg)
1.5″ of sand on a standard footprint
Sand density here is 1.5 kg/L and bags are 10 kg. Planted aquasoil at 2″ on the same 20 long is about 12 L — two 9 kg bags, not one.
| Tank | Footprint | Liters | 10 kg bags |
|---|---|---|---|
| 10 gallon | 20×10″ | 4.9 L | 1 |
| 20 long / 29 | 30×12″ | 8.9 L | 2 |
| 40 breeder | 36×18″ | 15.9 L | 3 |
| 55 gallon | 48×13″ | 15.3 L | 3 |
| 75 gallon | 48×18″ | 21.2 L | 4 |
Worth knowing
- Rinse inert sand/gravel thoroughly; many aquasoils are used unrinsed per brand instructions.
- A thin sand cap over aquasoil reduces clouding and keeps fish from digging soil up.
- Mesh bags of inert rock under the slope save expensive aquasoil in deep backgrounds.
Usual mistakes
- Buying by “one bag per tank size” marketing — always calculate from dimensions.
- Deep sand beds without circulation going black/anaerobic under decorations.
- Forgetting that driftwood and stone displace substrate — you may need less than the empty footprint suggests.
See also: Tank Volume · Lighting · Fertilizer