NEEED HELPPP new pvc overflow

[SublimeAquatics]

just finished making a pvc overflow described in the sticky thread above. i used 1.25 in pvc and i have a rio 3100 pump. i wanted to use this for my 100 gallon tank but the water flow is really slow and i cant even turn my pump up full power. should i get bigger pvc pipe or what.

 

[beex215]

pvc output is slow? 1.25 is large enough to handle 100's of gallons. its probably not fully primed or has air in the tube


or

if i remember correctly in the thread you may simply have used too big of a pvc pipe

 

[SublimeAquatics]

well the pump pumps like 700 gallons of water and the pvc can only handle like 350 gallons. so what size pvc should we use

 

[nolapete]

need a picture of your overflow. I have two quiet one 4000s on my 210 with 2 1" pvc overflows and they handle the flow with no problem. I suspect you have air in your overflow and don't have a check valve on the top, but I could be wrong. 1 1" overflow properly designed and primed should handle 700 gph

 

[CHOMPERS]

should i get bigger pvc pipe or what.

I'm gonna go with "or what".

 

[fhawk362]

Most people suggest using multiple inlets leading to the one sump, Or you could restrict the pump flow, most people use one inch pipe, I'm surprised the pvc size cant match your pump, do you have an airline check valve, i heard sometimes this can happen if you don't have one.

 

[bitteraspects]

well the pump pumps like 700 gallons of water and the pvc can only handle like 350 gallons. so what size pvc should we use

actually, 1.25" PVC will give you way more than the 700GPH your pump is pushing.
most likely your overflow was either not built right or was not properly primed.

 

[scottswald]

3/4 inch overflow pipe will be plenty big enough for a little 100 litre tank yeah, with a 10x turn over rate?

 

[bitteraspects]

Should be fine.
You should be able to get up to 12x on a 3/4" overflow.

 

[calicichlid]

1.25 is little dificult to keep prime it seems to building air pockets.