How much substrate do I need for a 55 gallon tank?

For a 122 x 33 cm footprint at a 3 inch average depth you need about 31 litres: roughly 31 kg of aqua soil or 46 kg of sand. At 2 inches it is 20 litres.

What size heater for a 55 gallon planted tank?

A 200 W heater. Once substrate and rock are in, a 55 gallon holds about 170 litres (45 gallons) of water, which works out to 4.4 W per gallon.

How much filter flow does a 55 gallon planted tank need?

Aim for 680-1020 litres per hour, which turns the water over 4 to 6 times an hour. Planted tanks like steady, gentle flow rather than a jet.

Can a 55 gallon planted tank work without CO2?

Yes, with low-light plants: ferns, anubias, crypts, swords and vallisneria. The height means fast stems and carpets will struggle without CO2 and strong light.

55 gallon planted tank setup

Long, narrow and tall. A forgiving volume for fish, but the 21 inch height and 48 inch length make lighting the main decision.

Dimensions: 122x33x53 cm; 48 x 13 x 21 in outer
Water volume: 170 L; 215 L (56.7 gal) gross, less substrate and rock
Substrate, 3 in average: 31 L; 31 kg aqua soil or 46 kg sand
Heater: 200 W; 4.4 W per gallon
Filter flow: 680-1020; litres per hour, 4-6x turnover
Light timer: 7-8 hours; with CO2 running

Lighting

At 122 cm long this tank needs about 120 cm of light coverage. We do not stock a bar that long yet, so look for a single 120 cm full-spectrum bar rather than two short ones with a gap.

See all planted tank lights

Filtration

Target 680-1020 L/h, which is canister territory. Our filters top out around 100 L, so pair a canister rated for at least 170 L with our media: ceramic rings for bacteria, foam pads for mechanical.

CO2

Recommended. At 170 litres a pressurised system is the easiest way to hold steady CO2 for carpets and stems.

CO2 option

CO2 Starter Kit - Regulator, Diffuser & Checker

Regulator with solenoid, atomiser and drop checker; you add a refillable cylinder.

$110

Substrate by depth

Slope it: shallower at the front glass, deeper at the back. The average depth is what sets how much you buy.

2 in average

20 L

20 kg soil, 31 kg sand

3 in average

31 L

31 kg soil, 46 kg sand

4 in average

41 L

41 kg soil, 61 kg sand

Custom tank? Use the substrate calculator

What to plant

Suits: Large community planted tank with background jungle and open midwater.

Vallisneria and Amazon swords at the back
Java fern, Anubias and Bucephalandra on wood
Cryptocoryne and Marsilea in the foreground
Floating plants to tame the light on a tall tank

Fish and shrimp

Room for a school of 20 tetras, a group of 8 corydoras or a bristlenose pleco, and a centrepiece such as a pair of angelfish.

Mistakes that cost people this tank

1Light that does not span the tank. You need about 120 cm of coverage; a short bar leaves both ends dark.
2Thin substrate. 48 inches of footprint takes a lot of soil; budget for it before you buy plants.
3Single small heater. Two smaller heaters at each end hold temperature better than one large unit.

Quick answers

How much substrate do I need for a 55 gallon tank?: For a 122 x 33 cm footprint at a 3 inch average depth you need about 31 litres: roughly 31 kg of aqua soil or 46 kg of sand. At 2 inches it is 20 litres.
What size heater for a 55 gallon planted tank?: A 200 W heater. Once substrate and rock are in, a 55 gallon holds about 170 litres (45 gallons) of water, which works out to 4.4 W per gallon.
How much filter flow does a 55 gallon planted tank need?: Aim for 680-1020 litres per hour, which turns the water over 4 to 6 times an hour. Planted tanks like steady, gentle flow rather than a jet.
Can a 55 gallon planted tank work without CO2?: Yes, with low-light plants: ferns, anubias, crypts, swords and vallisneria. The height means fast stems and carpets will struggle without CO2 and strong light.