how much is to much? (waterflow)
 

Is 4000gph on a 180g tank to much? Thinking of having 4 returns to spread it out. Then again I have a 1-1/2 hole,in my overflow, will that handle 4000 gallons?

not even close to too much....

I have the same amount of waterflow on my 50G...

i'm not sure if the lone 1.5" return will handle it...maybe.

Oh, sorry, read that wrong. Too much flow for the tank, no. Too much for that overflow, yes. Besides, you don't want 4000gph going thru your sump. Pods would be surfing in there!!

well I have a 30gal refugium, so not to worried about the pod life.
Newguy, you have 4000gph on a 50g tank?

Hi,

It is close to it, but not quite. Its probably more around 3600GPH or so. Mind you the tank is SPS only and barebottom. The majority of the flow (99%) is from the closed loop pump (Sequence Dart).

I have over 4000gph on my 140 and i know i could use more in spots. 1 1/2" wont do 4000 tho.

http://www.reefcentral.com/calc/drain.php

will tell you how wide the hole must me to handle flow. It says 2.6 for 4000gph.

hey thanks for the link, that's pretty cool.

Re: how much is to much? (waterflow)
 

Is that a single overflow or a pair of 1 1/2,s? Like Brad mentioned, its a lot of sump flow. I also think its to much for a single 1 1/2. I prefer keeping the sump flow around 1000 gph to 1300gph, or even less, and developing more in tank flow, with either closed loops or stream pumps.

I do know of many bare bottomed sps tanks that do push a very high flow through the overflows and sump, to keep the detritus suspended.