Happy Easter! Over flow problems

[plumber]

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

 

[cmaxwell39]

What size are the drain lines on your overflows? If they are standard 1" drains then they will only handle about 600gph a peice. You may just be trying to run too much flow for the overflows to handle.

 

[plumber]

Hi, Tank has standard 1" returns. I did notice that overflow on right side of tank seems to have more flow over the top then left side despite my efforts to assure tank is level out just a tad . Is there a way to compensate for this?
Thanks John

 

[cmaxwell39]

Do you have any way for air to get in to your drain piping. It sounds like it is starting a syphon, pulling the overflow down below the plumbing and then building back up (think of a toilet flushing). If this is the case then maybe providing a way for air to get in to keep the drain running smooth (think of venting the drain lines in your house so that drains run correctly). It could be as simple as putting a small air line tubing into the top of the overflow piping to allow a little air to get in. HTH.