overflow capabilities...

is there a limit to how much an overflow can handle? (I assume it based on pipe size)
Is there a chart or equation or anything to go by...?

 

Man I have seen a chart somewhere, so it does exist...That being said, I have 2 megaflows and it would take a hell of alot of water to back them up. I am running a Rio 2100 into each and they are not even close to capacity

 

1" schedule 40 PVC can handle almost 1000 gph. (960 or 980 is tops) 1.5" schedule 40 PVC can do nearly 2000 gph.

Keep in mind these are maximum numbers and any excessive bends may restrict flow.


These numbers are derived from formulas used in the plumbing industry. AGA/ aqueon says their overflows can handle 600 gph, and they use 1" sch 40 pipe. That may be for legal reasons.

 

this is kinda cool

GPM/GPH Flow based on PVC Pipe Size, ie, How much water can flow through Sch 40 Pvc Pipe Size 1/2" 3/4" 1" 1.5" 2" 2.5" 3" 4" 6"

although 960 seems high for a 1in i have always heard 600

 

Glad to see my memory is good. I have not even looked at that chart for a few years.

Read my earlier post about the 600 gph that AGA mentions.

 

haha, i had the reply page open while i was googling a chart

 

so i just bought a stronger return... at 4 ft head it is going to be putting out 840gph. I have a HOB overflow with 1" pipe so I should be okay without upgrading the overflow, right?

 

you can always throttle back the output side of the return pump with a ball (ok) of gate (best) valve.

I would suspect the 600gph standard is either based on their assumption that we're using a flexible line with various fittings which would restrict flow a bit, and so 600 is a good estimate. At any rate it's a good place to start on choosing a return.

or because the flow through the teeth cut in the overflows are more restrictive than the pipe, which would be a smart design.

 

lolo truthfully you wont know till you turn it on and witness it, i have a 1 1/2 inch single overflow on my 65 and ha it cant handle 500gph, its a used tank I got so idk what this guy did to the overflow but just try it out and if not working do like greysoul said throttle it back and prob solved

 

HOB overflows are usually restricted my the u tube. You may need to divert the flow from your new pump. Does your skimmer or fuge or reactor or any kind of device needing flow have a powerhead running it? If so, you can use the return pump to handle that powerheads job.