my set up at the moment is a 5.5 gallon with a few plants and a small 16gph(gallons per hour) filter. The recommended set up I think is 3.5 gallon or more set up with 1 pair or if its bigger like 5 gallons you could get a trio(Just a pair if there are A LOT of plants which mine will have before I get the female). Its also recommended that you have substrate which I dont have but what I'm going to do is cover almost half of the bottum of the tank with Java moss and the killies will lay the eggs on it. So your tank would be perfect with A good amount of plants, small D-I-Y sponge filter(or small filter like mine). Bottum covered with substrate(or java moss like I'm doing).1 pair of killies or if you dont want to load your tank up with plants(though its recommended even for a trio) you can get a trio of killies 1male and 2 females. If you're serious about doing it then I'll contact JayJay which has kind of been my go to guy and I'll get him to help you out. Also you can check out the thread between me and JayJay on the cyprinids etc. forum(lol did it in the wrong place but at least he found it, they are really considered oddballs). Another forum you could join that i have joined is out there but I'll only tell you if you are going to breed them.