Too Much Pump

jumpfrog

jumpfrog

Active Member
This is similar to Beefcakes question and I'm still confused on this plumbing stuff. Can someone help, please?!?
Here's the deal. I have a AGA 125 with twin overflows. I thought that each overflow 1" would give me about 600 gph. So I bought a mag 12 for my sump. It's pushing about your standard 4' head. I figured this would allow me to run the mag 12 wide open.
WRONG~!
It seems I have to have the pump throttled back almost half to keep from draining the sump.
From another post it seems that throttling back like that increases heat which may be why I'm sitting at 80F when my heaters are at 77.
Any help please with what I'm doing wrong.
 
S

sebae0

Guest
i use a mag 12 and unfournatly my tank is not drilled but i have a dual overflow with i believe 1" drains. this drain into my sump/fuge and is pumped back up at exactly 4.5' and i have no problems with it draining the sump. i estimated my duals at 1400gph.do you have enough water in tank to keep up with the overflows? also try to get broomer to respond hes awesome at this
 
rockface

rockface

Member
I have 2 1 and half inch drilled overflows, and I'm running a mag36, and a mag 9.5 @ 6 ft. wide open. 1 inch PVC plumbing, with 4 1/2 return clear lines.
 
jumpfrog

jumpfrog

Active Member
What do think I'm doing wrong?
When you say have enough water, do you mean to make sure the sump has plenty of extra water to give everything a chance to move through the system?
My sump has the line marked on it as the "water line." I thought this was where I should keep the water level. Is it really the "minimum" level instead.
If I fill the sump up to the point to where I have just enough to allow return water in case of power outage is that the better way to allow full pump flow?
Thanks for helping this handicapped plumber!:(
 
rockface

rockface

Member
do your over flow hoses have a lot of bends in them. I really think it should be fine with your pump you have. Make sure something isn't stuck inside the tubes. I run valves on all four of my returns, but each are opened fully.
 
broomer5

broomer5

Active Member
jumpfrog
Assume all 125 gallon All Glass tank are the same.
Dimensions of 72 x 18 x 22 inches.
For every inch of water in the tank - it equals 5.6 gallons.
Assume every Mag12 is the same.
Pumps out around 1100 gph @ 4 feet of head.
DO NOT assume that all sumps are the same.
Here lies the problem with using large capacity pumps.
If you have a small sump - and the water level is not deep enough and has a large enough volume - then when you turn on the pump - it will suck the sump dry BEFORE the display tank's overflow water begins draining back down to the sump again.
If you have a very large deep sump - that holds a ton of water - when you turn on the pump you may not notice much of a water level drop in this big sump at all.
The amount of water the sump "holds" at normal operating conditions needs to be determined.
Then turn off the pump and watch the water rise up in the sump.
If you still have "room" before the sump overflows - then pour more mixed areated saltwater into the sump.
You need enough saltwater in the sump to prevent what you're already experiencing.
It's a balancing act.
Enough sump volume to insure the pump doesn't suck air
VS
Enough room in the sump to handle the "draindown" water from the display tank upon loss of power, prior to siphon break.
Two 1" overflows should handle the Mag12 wide open flow - without the need for a throttling valve ~ PROVIDING you have enough sump capacity to run this return pump.
Confused or is this any better ?
 
jumpfrog

jumpfrog

Active Member
Brian, much better. I'm going to give all that a try tomorrow. Bought the sump from swf.com rated at 200 gallons. Here's the pic. I'll chime in tomorrow for results.
 
jumpfrog

jumpfrog

Active Member
Thanks for everyone's help. Adding water to the sump was the answer. I didn't have enough water to let the pump do it's thing.
Wide open and workin' great.
Thanks again.
 
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