Thank you all for replying!!! I'll start with the most common questions.But first I will give you some information about my aquarium: 12lt, 2 anubias
(barteri var nana),about 20 little stones( no gravel), there is no filter only air pump, I use tetra aquasafe and tetra flakefood for goldfish.
1.How usually should I feed it?
2.How many times should I change the water in a week?
3.Do I have to put a filter in?