I will get told off for this. This is my 100 liter tank that I am raising 25 Electric yellows in. I don't care about the algae, they are happy and it gives them lots of stuff to chew on. You can see how high I have built up the rocks. Every fish will find its own space. As a foot note, we only think a tank needs to be clean, as long as it is a healthy environment the fish don't give a dam.