Another DIY PVC Overflow question!!!

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B

bwah

Feeder Fish
MFK Member
Jul 30, 2010
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Adelaide
Hey guys,
this is my first post.. great forum i must say
have found lots of great information here

i just built a 1" pvc overflow for my 6x2x2
tested it out today, and it barely flows
unless i block the siphon break, but then it would overflow if a power out occured, thus defeating the purpose...

now after some research i think ive found my problem
i initially calculated my flow rate on the mass flow rate of a 1" pipe
so i went ahead and built the overflow matching it with a 1200GPH pump
using this design



now according to Pipe Sizing Charts and Flow Rates sticky by CHOMPERS this is a Gravitational Horizontal Flow which would only be good for 1" = 6.253GPM which is 375GPH
thats a massive difference compared to the 1000GPH i predicted
no wonder it barely flows!

so it looks like i have to build a Gravitational Vertical Flow setup like this


to exceed the flow rate of my 1200GPH pump i would have to build it using 1.5' PVC = 22.5GPM = 1350GPH with a Min. Vertical Length of 1.5 = 20"..
correct? or is there a loss in flow due to elbows etc. i have to account for ?
also when referring to the diagram, is the Min. Vertical Length the A pipe or the B pipe ?

really appreciate some help with this, as i have already wasted time and $ on 1" stuff.. who said diy was cheap?

thanks
 
well i took a punt and went for the 1.5" setup
works a treat, keeps up with my pump and maintains level in sump
ill post some pics when i get the time
 
"works a treat, keeps up with my pump and maintains level in sump"

Good to hear. As a side note it is the _tank_ level that is maintained.

The level in the sump fluctuates due to eveporation, water changes, adding a rock or a monster fish...
 
So, If one builds an overflow exactly the way you explain in the sticky.... equal loops, T at the waterline and a check valve.... And it syphons but not alot of water and when you kick the pump on it wont keep up..... Does this mean its still getting air?
I built this unit out of 1 1/4" and My pump dosent flow too much... The water level rises till it pours out and even tough it is draining it isnt draining enough or fast enough?
 
It's not supposed to be a syphon
It's supposed to be a self priming drainage system
If you pump overflows your tank
It's too small in diameter or not primed correctly

RE: "this unit out of 1 1/4" and My pump dosent flow too much"
I'm guessing there is air in the uploop
 
Bit slow at times me, i have just done the same setup, the 1.5 inch that is, i have done a new thread with pics of it `before i glue it` thread.

Can you have a look at it mate and tell me what you think as your is working.

Although i have 2 2000lph return pumps ( about 45gph )

cheers kida


wayne:)
 
waynes world;4600085; said:
...2 2000lph return pumps ( about 45gph )...
Click to expand...


DOES NOT COMPUTE
 
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