thanks for the quick reply severum. you seem to always be answering all my questions thanks =). and i believe my tank has finished cycling. tested my water for the past couple of days its only showing nitrates at 20. i will get more rummy nose if other tetras wont school like them. they look pretty cool schooling! or maybe i can have two different schools of tetra 5 each? ultimately i am planning to give back the green puffer i have and have about 10 tetras, 4 angelfish, 2 of those cleaning catfishes, bunch of ghost shrimp in my 40 gallon. what other fish should i get? (adding them very slowly of course).