diy overflow

[nolapete]

http://flexpvc.com/WaterFlowBasedOnPipeSize.shtml

Your numbers are wrong for flow rates. I don't know where they are from, but I'd trust a place whose business is flow.

The reason you need the aqua lifter is that your pipe is too big for your flow and it is allowing too much air in.

The only thing fishy about my setup is that there are fish in the tank.

 

[Iffrat]

http://flexpvc.com/WaterFlowBasedOnPipeSize.shtml

Your numbers are wrong for flow rates. I don't know where they are from, but I'd trust a place whose business is flow.
The reason you need the aqua lifter is that your pipe is too big for your flow and it is allowing too much air in.

The only thing fishy about my setup is that there are fish in the tank.

well i would much rather have way to much overflow .. then not enough .. i took the information that was available to me and made my decision .. and everything is working great .. i guess there is no reason to change anything .. the method being used is proven so i dont know why change it ..

i dont need the aqua lifter .. i use a aqua lifter .. is there a problem with that?

and if it works then ok .. good for you .. im glad it works .. but is there a reason why i must use the same set up as you? is there a problem with my set up?

 

[nolapete]

No, you can do whatever you want. I just inquire when people reinvent what already works to see why. If there's something that works better, I'm all for it.

 

[Iffrat]

No, you can do whatever you want. I just inquire when people reinvent what already works to see why. If there's something that works better, I'm all for it.

oh i have no idea if it works better .. i just used the sticky and made the set up ... the only difference from the sticky is the T where the aqua lifter is attached and i use a 45* angle for the intake rather then just the flat pipe .. everything else is per chompers post and the information on the sticky for pipe size and set up ..

 

[Dane]

The flow rates on http://flexpvc.com/WaterFlowBasedOnPipeSize.shtml are not correct. They show a 3/4 pipe able to do 660gph. I can tell you that isn't true as I just built two overflows with 3/4 and they can't keep up with my pump which flows around 900gph given the head that I have. The sticky that shows a 3/4 around 300gph is more accurate.

 

[Iffrat]

dane i have a feeling your correct ... i am going to try to bring a flow tester from work and see what i can pull with my set up .. if i can i will let everyone know what i find .. but i am not sure what the expected flow rate of the overflow set up with 8 or so 90* turns .. i have a feeling that the flow rates that are given are how much can flow in the BEST CASE with no turns bends or siphon just 100% free flow from top to bottom ..

maybe if the tank had a hole drilled in the bottom and you just drained the tank right to a drain ?

 

[Dane]

dane i have a feeling your correct ... i am going to try to bring a flow tester from work and see what i can pull with my set up .. if i can i will let everyone know what i find .. but i am not sure what the expected flow rate of the overflow set up with 8 or so 90* turns .. i have a feeling that the flow rates that are given are how much can flow in the BEST CASE with no turns bends or siphon just 100% free flow from top to bottom ..

maybe if the tank had a hole drilled in the bottom and you just drained the tank right to a drain ?

The 90's definitely slow things down. If you had a drilled tank then you would actually have pressure applied and that would increase the flow rate. I thought about doing a flow test when I built my overflows, I ran out of time to play with it. I think I'm going to rebuild mine using 1" or maybe 1"1/4. I have some modifications I want to try anyway.

 

[nolapete]

You're correct that any 45s, Ts, or 90s slow things down. Their flow rates are for the flexible PVC they sell which would be the same as a straight run of the same size pvc. To properly calculate the flow rate of a pvc overflow, you would have to calculate the flow reduction of each fitting used and subtract that from the pipe size flow rate. The flow rate for pipe sizes on the flexpvc site is correct. You're not comparing apples to apples though.

 

[Iffrat]

You're correct that any 45s, Ts, or 90s slow things down. Their flow rates are for the flexible PVC they sell which would be the same as a straight run of the same size pvc. To properly calculate the flow rate of a pvc overflow, you would have to calculate the flow reduction of each fitting used and subtract that from the pipe size flow rate. The flow rate for pipe sizes on the flexpvc site is correct. You're not comparing apples to apples though.

yea i think flex pipe is showing max straight line flow rate .. where the sticky numbers are more like the number you would expect to see using the build ..

but then again you said you have a PVC overflow set up and have way more flow then the sticky says .. so who knows ...

 

[nolapete]

Likely not that much more though considering head pressure now that I'm thinking about it. Interested in finding out what your flow meter indicates.