1/2 inch overflow problems

[carsona246]

So i decided that I wanted to actually build a sump for a ten gallon tank that had no mechanical filtration. Made a small overflow out of 1/2 inch pipe. The problem is while it's flowing it isn't flowing strongly. Maybe 1 gph slow. I havn't put in the check valve at the top yet, but I think everything else should be just fine. Any ideas on what might be wrong?

 

[carsona246]

wait, pretty sure siliconing it might help. For some reason I thought I could do a test run without the silicone

 

[nes999]

wait, pretty sure siliconing it might help. For some reason I thought I could do a test run without the silicone

siliconing what?

did you use pvc cement on all the connections?

 

[carsona246]

nope, was planning on silicone. Should I use pvc cement?

 

[jsodwi]

pvc cement

 

[carsona246]

really? I guess I'll go run to the store tommorrow and find some aquarium safe pvc cement. thanks for the help, I would have definatly siliconed them tonight had you guys not let me know.

 

[carsona246]

Ok, so it is now cemented, and it won't even drain a little. Anyone have any idea as to why? It's been a while since I've researched overflows/sumps, but I've been going through past threads and I'm pretty sure I did it right.
Heres a picture of it just in case that works. still havn't installed a check valve, but if I remember right that shouldn't stop it from being primed properly and starting a siphon.

 

[carsona246]

Ok, been doing some research and i think the tube where water is coming in is supposed to be taller than the t. Is this correct, because I think this is my problem

 

[Gator]

The more angles you add to pipe the more you restrict your water flow. 1/2 pvc is already a small diameter and isint going to let that much water flow through it.

 

[carsona246]

I'm going for low flow, I plan on using a powerhead as a pump. If I manage to get 50 gph I'll be more than happy, and will probably lower the flow with a ball valve I intend to install. I'm pretty sure this is a standard overflow design, I pulled it off a sticky.