Hi All, New to the forums. I have had aquariums on and off my whole life with moderate success. My last tank was a 29ga that I had drilled for overflows with a 10ga DIY sump. Unfortunately I had to move and didn't have room to take it with me. While it worked, I wasn't completely happy with it. Now, I plan on building a small system to see how it works before building a larger system once our new house is complete :;banaman. My system will be a 6.5ga (plan on setting up at work so can't go big) acrylic tank that will have a 1/2" overflow drilled into it. That will overflow to a 10ga sump that will probably house ~8ga of water. A canister filter(80gph) will draw water from the sump and return the water to the tank (still thinking about this. may have the water drawn from the tank, sent to the sump, and then returned to the tank). Anyways, so my system will have ~15ga of water. I know that the extra volume of water will allow the system to hold extra fish. However, I'm more worried about swim space. I'm looking for ideas of fish and quantity that the system might be able to accommodate. I know typically this tank is suitable for a betta and that is about it. Don't get me wrong, love betta's, have one my niece named Cocoa. However for this system I'm hoping with the extra water and flow I can put something a little more active in. Possibly 3-4 small fish. I look forward to hearing from you!