Low flow with Varios 4

BattleReefer · Aug 8, 2023

So my tank has been up and running for a while but my flow reading doesn't seem right. I originally thought it was a sensor error but after a physical measurement, its accurate. The tank is a Cade 1500, which is around 170 gallons. I have a varios 4 as my return. The only thing directly inline with the return is a 57W aqua UV and the 1" flow meter. My flow readings are stable but generally only reach about 290 GPH with the pump at full power. There are 4 elbos and 2 45 degree fittings in the circuit, which I know isn't ideal, the head height is about 4 feet. That being said, I wouldn't expect the flow to drop off that considerably from the 1050GPH at no head pressure. My question is, do you think this sounds right and I simply need to start running a larger pump, or is there something else in play I'm missing.

blaxsun · Aug 8, 2023

That's probably accurate. Each 90° elbow and 2x45° elbow count as 1 foot, so you're looking at about 9 feet of head height. You'll probably want to get a large pump. I run a Sicce SDC 9.0 on my 200-gallon system and get somewhere between 650-750Gph @45%. (Addendum: revised because I can't add this morning)

Zero_Cool · Aug 8, 2023

Varios pumps do not handle head pressure well. Rough calculation of your plumbing:

4' vertical = 4'
4 90s x 1' = 4'
2 45s x .25' = .5'
Estimated 3' horizontal x .5 = 1.5'

That's an estimated 10' head pressure without taking into consideration the input/output 90s and reducers of the UV. Based on the flow chart for that pump I would say 290 gph is accurate.