Help! What am I doing wrong? Air in overflow pipe

[frootloops]

Exactly! Pipe one should be able to flow wide open. Pipe two ideally should be wide open but none of this is exact science so pipe two you throttle back so it maintains a syphon all the time, no gurgle. Pipe three is right at surface level and will take the extra and allow for fish movement/splashing and so on it will have some noise but not too bad. Pipe four is just above surface for overflow prevention, just incase a lettuce leaf or something clogs one of the pipes. Weird stuff happens lol.

Edit: there's a thread with this exact set up and I can't find it! Its something like" quiet over flow" or "silent over flow???" Most likely it's another forum? I will find it and post the link. A much better explanation and most likely a detail or two I missed

Oh! Now I totally get it!

2 pipes are below water level using a u bend so it will be quiet. (2-3 inches below)
This creates a full siphon IF the return pumps are strong enough to flow more water than the 2 pipes can handle. Now this necessitates a third overflow which is higher than the 2 180 pipes. It will not be too loud because the water flow in the third overflow is nowhere near the max capacity of the pipe. 4th overflow pipe is there as a failsafe.

Did I get it right?

 

[frootloops]

I tried this on a single pipe system (no venting) and it was a failure.

So the 180 pipe that points down does not work? (Let's say it's made up of a straight pipe, and 2 elbows on top to get it to point down.)

If so should I put a vent at the top so It will flow better?

 

[Egon]

Oh! Now I totally get it!

2 pipes are below water level using a u bend so it will be quiet. (2-3 inches below)
This creates a full siphon IF the return pumps are strong enough to flow more water than the 2 pipes can handle. Now this necessitates a third overflow which is higher than the 2 180 pipes. It will not be too loud because the water flow in the third overflow is nowhere near the max capacity of the pipe. 4th overflow pipe is there as a failsafe.

Did I get it right?

Okay this part is tricky. If your U shaped pipes are too far below the surface then your going to syphon your tank dry and over flow your sump if you have a power outage!
I would go as close to the surface as possible. If your too close to the surface then your going to get a whorl pool sucking air down the pipe. LOL This is probably just funny to me because I dork around with plumbing a lot cuz I think it's fun.

 

[meerak]

hi. not to mess with your plans but i saw one of these set up here on mfk. just throwing it out there. good luck on your project keep us updated.

 

[frootloops]

hi. not to mess with your plans but i saw one of these set up here on mfk. just throwing it out there. good luck on your project keep us updated.

Won't all the long pipes and elbows cause the overflow to run slow?

 

[epond83]

No because with this set up there is no air in the line, so the pipe can run at max flow

 

[Egon]

Yes, it will be slower than the siphon method we talked about previously. It also has exposure to air so it will have some noise.

 

[frootloops]

No because with this set up there is no air in the line, so the pipe can run at max flow

There's an air vent on top of the pipe in the picture

 

[frootloops]

Yes, it will be slower than the siphon method we talked about previously. It also has exposure to air so it will have some noise.

I'll try that 180 pipe you suggested. I'll post updates

 

[Egon]

I'll try that 180 pipe you suggested. I'll post updates

Looking forward to it. Hopefully you get the syphon started with out issues. Some guys use two 90's and don't glue the joints, then rotate it to point down after the water starts flowing. Then you gota get your pump turned on in time before the water level gets two low. Once you have the syphons started and your pump is flowing then you need to adjust your ball valves to control the flow and balance your system.