over flo problems! Please Help

[plumber]

Happy Easter! Over flow problems

[hr]
Hi , Setting up 150 today dual overflows. I have a wet/dry made for tank I decided I would like more flow so I added another pump to drive system.My thinking one for each overflow pump1 1500gph, pump2 unknown, problem is return to wet dry sounds like waves crashing against rocks. I looked at overflows and noticed water rising then falling in sync with wave noise. any help or is this normal? The system is made by all glass aquarium and is a matched set.
Thanks John

 

[scsinet]

AGA's megaflow overflows - which is probably what you have - are rated for 600gph each. So a 1500gph pump, by itself, would overwhelm the overflows.
That rising and falling action... sounds like you aren't venting air out of the standpipes properly. Is the top of the standpipe (where the air-vent is) above the waterline?

 

[taznut]

depending on the return pipe sizes and the number of elbows,ballvalves, etc your pump is a lot less than 15gph by the time it gets to the tank... you probably do have a little too much flow but i agree with scs, its probably more of a venting problem...

 

[posiden]

If you overpower a pipe with to much flow you won't be able to vent it proper.