My fish tank is farting!!!!!

[minnow me]

Hello everyone, first time posting on this board. I'm setting up my first saltwater tank, and setting up my own DIY Sump with a Rio 2100 for my return pump. I have two 1" holes with two 1" bulkheads. The guy at the LFS, told my to use 1" piping going into the sump and 3/4" piping going out from the sump back into the tank. I plumbed it like he said, but I had to throttle down my pump quite a bit so my tank wouldn't overflow with water. So then i tried 3/4" piping going out and 3/4" going in. Now I can turn up my pump full blast and water is being drawn out from the tank like crazy. It sucks out so much that it's beginning to suck in some air, and is making an annoying farting noise. Seems like the 3/4" piping is creating some kind of suction that 1" wasn't.
I'm really frustrated at this point. Any advice or suggestions would be appreciated.

 

[minnow me]

I forgot to say that the 1" holes are drilled in the back of my tank with 1"bulkheads. One for water going out and one for water going in.

 

[saltwatersensae]

if you place a small tube in the bulk head coming out of the tank into the air it won't make that sound anymore. think of it as a straw you drink out of letting the air that getts sucked in out. If you have a lillte gaurd thingy so things don't get sucked in just drill a hole at the tip and then and then use a a tube that has a 90 degree bend in it. then move the tube back and forth 'till you find the sweet spot that lest all the air out.
[ November 14, 2001: Message edited by: Saltwatersensae ]

 

[minnow me]

Thanks for the help Sensae. I'll give it a try.

 

[saltwatersensae]

No Problem