closed loop using overflow as water source

[JREEF]

My set up:

I have a 29 Gallon that I had the back of drilled. I then had a custom acrylic overflow made. The overflow is 3 sided with the three sides all 6 inches in length. The overflow goes from the top to the bottom of the tank so I have room to put rubble live rock. However, The 1 inch can not handle the flow I NOW want(mag 12).

Here's my idea.
Drill 1 inch above the bottom of overflow for 1/2 or 3/4 bulk head. Connect mag2 or mag3 in overflow to bulkhead, Then connect to a spraybar under liverock.

This should pump out about 200 or 300 gph and the rest will go down the 1 inch drain pipe to the sump.

Sorry that I have no pictures. Let me know what you think.

[wanareef]

dbl post ?

[Geoff]

the problem is that the overflow itself can only handle so much flow over its weirs.

G~

[JREEF]

My overflow can handle the flow of the mag12 wide open (pumped up 4 feet) and I tried a small 300 GPH poerhead that I hooked up to flexible hose and pumped out simultaneously and the overflow was fine. It worked for about half an hour and am wondering any consequences. So will it work longterm??

Also any ideas of how to stop water from coming back through the pump when the pump is off? Can I trust a check valve?

[Geoff]

check valves can not be trusted. they get clogged over time in SW. there are also few that do not contain metal parts.

G~