Intake size for predrilled sumps??? Help Please???

[doubledragon]

I have 8 thirty gallon breeder tank's that are predrilled in the top corner. The outside diameter of the hole is 7/8". Is that o.k. for a sump? I would like to have a high flow rate going through these, but do not want the water to shoot in to the sump so fast that it will bypass the filter pad instead of going through it.

If I put a elbow on the inside of the sump, that is bigger than the pvc going through the predrilled hole, will that lessen the pressure that is hitting the filter pad??? What if I had it come into the sump and put two elbows on it would that work?

Also how big of a powerhead can I put on the outtake with a intake this size???

 

[doubledragon]

Is there a certain gph that should be pushed through certain size predrilled holes. If so what kind of ranges would they be.

 

[duanes]

A 7/8 hole is small, and depending on your pump size, you may need more outflow area.
You may want to ad a T above that area to split your flow and have 2 flows to the sump.
If you put a PVC valve below the T, you can adjust the flow to how much you want coming from each outflow. You can also run the above outflow to a different area in the sump.
Another outflow would give you a little insurence in case one gets plugged, and a 7/8 hole is easily pluggable.