Well with the help of you guys i have sorted my 15 gall overstocked tank and took most of the fish out of the tank that i had in and replaced them with tetra,s for the time being,12 in total for now. I am looking at getting a few Cory's next.Could you tell me if the stock filter that came with the tank is adequate ? As i was given a power filter yesterday that is off the same size tank as mine but it was included in an aquarium pack that a friend of mine had but he has gone off the idea of keeping fish as he says "its to much hassle". Any help would be greatly appreciated. I have asked a similiar question previous but i do not want to install the power filter incase it creates to much current in the tank.