Drew 43920

I suction the gravel, then I add new water. Both these activities stir up poop. Some of that poop is sucked up by the filter and the bacteria in the filter neutralizes it . Right ?
Drew

Lucy

In a properly cycled tank, yes it should. If there's that uch waste in the bottom, you might want to step up the vacuums until most of it is cleared out.

Jess

Right! But if your tank is planted. They should help with mulm left in the gravel.
With a planted tank I believe you lightly clean the top surface so as not to disturb the root system of your plants. When the filter pulls in water and debris the bacteria in your filter breaks down nutrients. Eventually your filter will get clogged and you'll need to swish it through a pail of aquarium water to dislodge solids.

Jess

Good point Lucy. If your tank is still dirty. More water changes are needed.

Peterpiper

IMO, It is better to remove as much of the wast as posible when you can.
Wast that is left in the tank or filter will break down to nitrates.
I understand that a planted tank requires food for the plants, but over time some of the wast will get to the root systems.