Beananimal flow questions


New member
I set up a bean animal overflow in my 210 gal. I'm new to aquariums, so maybe i'm missing some very basic thing.....

Using all 1.5" for the drains to sump where it marries to 1" sump intake lines, and then run all 1" just till where the pipes take their final move to attach to the 1.5" bulkhead on tank. Sump is in basement, directly under tank, about 9-10' head height. Pump is rated for 1326 GPH (Little Giant 'Quarium Series Magnetic Drive Pumps 4-MDQX-SC) but I assume I am losing a bit of that due to my long return of 10' in height and the necessary bends in plumbing the inline heater and UV.

Problem is I have my main valve fully open (I have a gate valve, but so far no need to close or adjust it seems) and it is taking full flow. The backup drain is also running almost fully, so much, it is gurgling air. If I clog the airline tubing in the 2nd drain, it does fully flush the overflow very very fast!.

From all I read, my main should be dialed down and the 2nd should be taking very little flow - this isn't my case!

If I do dial back the main gate valve, the pump starts to empty the sump.
Do I just have too high capacity of a pump? If so, can I throttle it back with a valve, and of so where in the line of plumbing would I do that:

Sump--> Pump --> Heater --> UV --? Back to tank

Maybe I need larger airline tubing on the secondary overflow? Now i'm using standard sized aquarium tubing, i think like 1/4" OD.

Appreciate any thoughts.