overflow ?

[xboroinc]

i am running two 55 gallon tanks. with a sump the pump is a900gph pump. what size over flows do i need for the tank?¿? i have ball valves on the hoses to controle the flow rates of the water flow..HELP.new to sumps

 

[hondas3000]

The bigger the better, but 1.5" will do. You rather have bigger hole then smaller one.

 

[KaiserSousay]

When I set up my skimmer style overflow, I had 3, 1 1/4"I.D. U tubes..started with 1, not enough flow..added another, much better..tried the third, too much..overflow box had 1 1/2" line to the sump.
Trial and error..as was said, bigger is usually better, but, not always.

 

[xboroinc]

okay thnx