How does the filter work?

The bubbles

Bubbles are created by the air pump. The air pump forces air through the base of the aquarium creating air bubbles which rise up through the bubble tube. When the bubbles hit the surface, oxygen is released into the water. Surface agitation also allows carbon dioxide to escape out of the water.

This helps:

force water down through the filter
fish to breathe
beneficial bacteria to do their job
plants to breathe at night

The sponge and fine mesh

These provide mechanical filtration, working like a waste bin, by trapping solid particles of waste and debris keeping them out of the water.

This helps:

water to look crystal clear
stop solid particles
damaging the fish gills
keep levels of pollutants low

The activated carbon and resins

These provide chemical filtration by absorbing some nitrate, phosphate and other chemicals from the water.

This helps:

remove colour from the water
reduce the build up of nitrate and phosphate

The ceramic media

The rocks at the base of the biOrb provide an ideal home for filter bacteria to live, multiply and work.

This helps:

remove toxic ammonia and nitrite from the water

Filtration cycle

Fish eat food, the waste produced by the fish (ammonia) is consumed by the filter bacteria and turned into less harmful pollutants like nitrate. Some of these pollutants are absorbed by active chemicals in the filter cartridge and eaten by plants. The rest must be diluted with regular partial water changes.

The more fish food or fish that enter the aquarium, the more pollutants are produced as a result. If these pollutants build up they will encourage green water and poor fish health.

Good aquarium hygiene and careful feeding will keep levels of pollutants low.