I have a 40 gallon tall with two HOB filters, one is a penguin 200 and the other is an emperor 280. I need to keep a good currant in the tank for my bamboo shrimp so they are able to get the food that is in the water for them, but also need to keep it calm for the fish that stay at the top of the tank.
How much circulation is necessary to keep a good amount of oxygen in the water?
Also, how high should the water level in the tank be? I don't have a powerhead or airstone, just the two filters, I constantly worry that the fish wont have enough oxygen if I feel the tank to the top, right now it is about two inches from the top of the black trim.
Thanks in advance for all your help.