need help on overflow rate

[Olivier]

hi everyone,
I need your help on increase my overflow rate. I have an calioverflow (cut the back of my tank) I use 2 inches pipes for the drain to my sump. I got 5gallons in one minute. So i figure the flow rate is 300 gallons per hour. Can someone help me how can I increase the flow to higher? Larger overflow or what?

Olivier

 

[Hawkeye]

what size pipes are they? How did you calculate 5 gallons per minute?

read jim roth's tank thread - he did a calfo overflow
http://www.njreefers.org/joomla/index.php?option=com_smf&Itemid=26&topic=6799.msg65673#msg65673

 

[Phyl]

If you have even one 2" pipe the rate should be more than 300 gph. My 1" pipe does 600. How wide is the overflow area? What is limiting you to 300gph? What would happen if you pumped 800gph at it? Where would it fail? Would the tank level get up too high? The water drain from the overflow area too slowly?

 

[BobCReef]

Oliver what you are measuing is your current rate of overflow not its capacity. As Phyl said when you increase the rate of the return pump at what point does it pump more than will drain. This is likley limited by the overflow

 

[Olivier]

If you have even one 2" pipe the rate should be more than 300 gph. My 1" pipe does 600. How wide is the overflow area? What is limiting you to 300gph? What would happen if you pumped 800gph at it? Where would it fail? Would the tank level get up too high? The water drain from the overflow area too slowly?

Phyl,
I can not answer all of your questions but I knew that I used 5 gallons bucket and in 1 minute, the bucket was full.  So  I just multiply that 5 gallons by 60 mins to get to 300 gallons per hour.

by observing the water flow during collecting to my bucket, I saw the water stream come down rather gentle instead of strong.  I will measure (ruler) the size of the overflow tomorrow and report here.

I will see if I can get a stronger pump to pump the water. as off right now, the strongest pump I have is Mag 12 which is not enough of flow since the top of my display tank is about 5 feet high.

how do you measure your overflow rate anyway?

 

[Phyl]

You've measured the FLOW properly, but not the capacity. By increasing the pump output (mag 18?) you would see where the failure point is for the maximum amount of flow you can put through the overflows and not... overflow!

 

[Olivier]

Phyl,
thank you. I will try your suggestion and report here.

 

[Phyl]

Good luck, Olivier. If you put a ball valve on the pump output you'll be able to dial control the flow to better measure the outflow and figure out which pump would best suit that without needing to be restricted