I set up my 12
gal Nano cube as a planted tank with a male betta. My only problem is the third compartment in the back tends to get low with water. I try to keep the tank full so I don't run into any problems. I have my heater in that compartment and I don't want the heater to run out of the water. When I keep the tank really full , my betta likes to explore and ends up in the third compartment. I end up having to try and net him and put him in the main tank. He doesn't get in any danger, but I just want to prevent it. I'm sure I am not the first one to have the problem. Is there a way to put something on it to make it higher so he can't get into filter part of tank. I know that was a little long, but anybody have any ideas?