Wow thanks for all the replies
What is MTS short for ?
I´m really looking into something that eats the waste in the water.
The water volume is about 70-90 liters.
This tank is a breeding project so snails that eat poop would also eats eggs right ?

I will be doing weekly water changes from now on, i didn't have any access to water in my basement so water change was a pain, but i figured out a solution.