sump question
 

im changing my sump and im not sure if the pipe that drains down from the tank can be submersed in the sump or if the water has to actually fall?

It can be submersed no problem. Usually quieter. WHat style drain/overflow are you using? With a Durso, you still get air, which will bubble to the top of the sump if you have the pipe submersed to far. WHat I did was have the drain go to a 90, then into a T on its side. the upper part of the T vents the air up, and water goes down. It can lessen the noise and splashing.

But on the 150g, I run a Herbie style with the gate valve, DEAD silent drain