PVC overflow

1" pipe all the way to the sump, and return i have a 3/4 pipe with a CA-3000, pump has to much power that drain wud not keep up so i put a check valve on the return pipe to dial/close the flow little bit..

 

im guessing that any plastic spray can will be reef safe right?

 

You mean, you put a ball valve to slow the flow from the return?

A 1" pipe under the absolute best circumstances is 600+ gph, but you're more likely to get 400 tops. To prevent bubbles, I would get as close to the flow it can handle.

As for the spray paint, I have no idea. I know a lot of people use krylon fusion.

 

If you used Krylon Fusion, the full cure time is like 7 days. It is fully "dry" after a few minutes, but doesn't fully cure or bond to the surface until 7 days later. I believe the check valve on the top of the U-tube is for starting the initial siphon and to clear any bubbles that may form in there over time. I would use it as I would hate to have to take an overflow apart later to add it.

 

The check valve is a necessity. It guarantees you are able to draw all of the air out of the overflow to get the siphon going. Once you have it going I would recommend an aqua-lift to keep it going because no matter what you do the pvc overflow is going to pull air into itself and there isn't near enough flow to push it on through. Eventually the siphon will break and you will have a flood. Same goes for any algae that build up inside and/or snails that crawl into it, so you'll need to keep it very clean inside or flow will slow to the point of siphon break. Speaking from experience here.

 

i just built one of these and it was so loud.... And it would stop working after about 15min because of air getting sucked into it... So i just threw it out and now im just going to drill the tank.... bottom line there not reliable..

 

i just put mine in the tank,its been working fine after couple hours now,i put a retainer on the elbow for snails n stuff,im just starting the cycle so i wont have anything till later...

 

i didnt put the check valve on the elbow like on the pic,i had to suck the air out from the exhaust pipe and cover the drain pipe by the sump to get it going,ones i did that it just keep working fine,i turn off power like 10 times and it will keep the shipon after i turn on the pump...

 

The problem isn't with it not maintaining siphon when it's turned off. It's gradual buildup of air bubbles in the tube, eventually leading to the siphon breaking. The thing that worries me the most about PVC overflows is that unlike a U Tube overflow, you can't see inside the siphon part, so you don't know what kind of bubbles are in there.

 

ummm,yea, true...