DIY pvc Overflow

[dhoffroad]

ok here was my last attempt last night I put letters on the tubes for ID so we can help me figure out how to make this work !! I don't think that C & F matter but figured I 'd put letters on them. I did have better flow in this configuration with D being long and the "loop" (E) being lower than in the pic in my last post. in this pic the "E" tube is also shorter than in the pic in my last post, heck I think I have changed each piece atleast 3 times guess just did'nt get the right combo....

[Geoff]

i need to think more on this but a quick look tells me your B or E are not long enough. this is causing the overflow to act completely like a siphon and not like an overflow. the inlets need to be slightly lower than the junction formed by E and F. this way when the water level drops below the inlets the siphon formed by the rest of the system does not keep trying to pull water. also adding the open tube near the juction of E and F allow air into this area to help stop the siphon. the system is designed to work when the water level in the display rises above the junction of E and F.

does this make sense?

G~

[kellymm]

What is it a pvc Spider ? Are they venomous?