Sorry, I don't think i am explaining myself well. I have just learned about sumps so i have no idea what the correct words would be. What I meant by input is the pump bringing the water down into sump, or is it just gravity fed? I think I just answer my own question. So, there is no pump on the entering side.
so do I need anything besides a pipe running from back of tank to the sump, what stops it from overflowing in sump. I am sorry if these are stupid questions its just I'm a girl that knows nothing about how this kind of stuff works and I didn't want to tell hubby what he needs to build until I have a better grasp on how it works. Thanks.
Btw I ordered the reef octopus 6 in sump, for 150 gallons.