The animals in you tank use the minerals and chemicals in the water, like your own body, do grow and stay alive, they also poo in the water and not all is removed by chemical and mechanical action, so you need to remove 10% water and add same volume new water.
In a small system it would be better to do 15 - 20% water change.
Someone said:
Dilution is the best solution to polution
and that is what you are doing by water changes.
In a small system it would be better to do 15 - 20% water change.
Someone said:
Dilution is the best solution to polution
and that is what you are doing by water changes.