amount of o2

[keith_r]

drilled holes have a tendency to plug, i have a tee with an outlet at each end of the gb, a valve can be used to adjust flow, but make sure you don't put to much back pressure on a pump or it will shorten the life of it..

[urbanfarmer]

Ultimately, you can't put too much oxygen in the water, but you can put too little.

[drdreww]

ok! thanks for all the replies guys. i will return multiple streams back into the tank, maximize surface area, and see how it goes!