BiOrb Tanks


BioGravel may be used to improve the filtration of Biorb and similar filters.

Biorb Capacity  
Model Amount of BioGravel Required
15 lt (4 gal) 1.5 kg
30 lt (8 gal) 2 kg
60 lt (16 gal) 3.5 kg
105 lt (28 gal) 5 kg

Lower/Cartridge Foam

All models use the same Lower and Cartridge Foam. We recommend you use Medium Foam for the Lower Foam.

The small Cartridge Foam (Fine) will be placed inside the center filter cartridge.   There isn’t space enough available below the foam to hold any worthwhile amount of BioGravel, so we recommend you place the Filter Starter Balls here.

Note that both of these Foams can be cut from sheets of our 6 1/2″ Foam sheets. Full size templates for the Lower and Cartridge Foams are provided at these links:

Lower Template

Cartridge Template

Be sure to set your printer to print full size when printing these templates.

Cutting Lower Foam

Upper Foam

The size of the Upper Foam depends of the model of the BiOrb being upgraded. We recommend you also use Medium Foam for this. It is placed on top of the Lower Foam. 

Full sized templates for the Upper Foam are available by following these links:

15 lt (4 gal) Upper Foam Template

30 lt (8 gal) Upper Foam Template

60 lt (16 gal) Upper Foam Template

105 lt (28 gal) Upper Foam Template

All the Foams and Templates

Final Setup 

Place the Filter Starter Balls into the Cartridge Basket.

Filter Starter Balls


Install the Cartridge Foam  into the top of the Cartridge and assemble the Cartridge.

Assembled Cartridge


Lock the Cartridge into the BiOrb and then insert the Lower Foam.

Lower Foam Installed


Then install the Upper Foam.

Upper Foam Installed


The BiOrb is now ready to accept the BioGravel. Rinse the media in tank water to remove any dust. Then spread the required amount over the Upper Foam and center Cartridge.

1.5 kgs of BioGravel


Fill the tank with dechlorinated water, turn on the air pump and run for an hour or so to make sure everything is running smoothly and there was no debris missed when you rinsed the Foam and Media.

BiOrb Running

Note that Prime and many other dechlorinators also bind ammonia, nitrite and nitrate. It has been observed that this delays or defeats the development of bacteria in Biohome® . We recommend using properly mineralized RO water or API Stress Coat dechlorinator.

Now you’re ready to start adding  fish. Please stock the tank gradually and keep the fish selection sensible. Your dealer should be able to help you select fish suitable for a small tank.

The BioGravel should cycle to control ammonia and nitrite in 2 to 3 weeks and nitrate in 4 to 6 months. Plants may be planted directly in the BioGravel.


The Cube can be upgraded just like the Classic BiOrb.

Biorb Cube Capacity
ModelAmount of BioGravel Required
30 lt (8 gal)3 kgs
60 lt (16 gal)4 kgs