Trouble restarting siphon

[jharding08]

I have a coast to coast overflow with a Bean Animal style overflow (full siphon, open channel and emergency drains).



I use the Feed timer on my Apex to stop the pumps while feeding my fish. When the timer ends and the pumps come back on, the C2C fills up until the water comes out the siphon and open channels, but the siphon never fully starts unless I take off the cap off of the siphon drain above the T, let all the air escape, then put it back on. It is silent at that point.

*Please note that I changed the drain lines to 45 degree angles instead of 90 since I took this picture to try to get the siphon to kick in easier.


I've waited 10 minutes for the air to purge out of the siphon drain, but it never does. I have the siphon line only 1" below the water level in the sump.



Anything I am missing? Could I just do 2 open channels? My pump is an Iwaki MD40RXT (1344 GPH)

 

[SGT_York]

Two open channels with that much flow will be crazy loud.

Taking the top off would only help if you have trapped air, that's all I can guess which means you have to many turns for good flow.

Try turning up the open channel for a test run to see if you can create enough pressure to flush it out. Increasing the pipe diameter could possibly help depending on exact causes. Venting the trapped air would work but you'd need to know where it was trapped.

 

[jharding08]

Try turning up the open channel for a test run to see if you can create enough pressure to flush it out.

Do you mean open the valve on the open channel more or close it more? Right now it is all the way open and the valve on the siphon channel is closed just enough to have water flowing through the open channel.

Right now I use all 1" piping. I really dont want to redo my plumbing again. Also, I use regular T's instead of Sanitary T's next to the bulkheads. IS that why the air is trapped?

 

[pscott99]

I don't think your gate valve should be wide open and shouldn't the emergency be wide open ? Close down the gate valve until the water flows in the emergency slightly. Then back off open it until you get the sound you want.

 

[Da Maui life]

I see many problems, when someone deviates from the “Silent & Fail-Safe Aquarium Overflow System” design you more then often end up with problems.


"The Open Channel standpipe is fitted with an airline that is curled back over and attached just below the trim inside the overflow box." You don’t have that airline going back into the over-flow see (System Description)
http://www.beananimal.com/projects/silent-and-fail-safe-aquarium-overflow-system.aspx Running horizontal return line can often create trapped air.http://www.beananimal.com/media/4054/back-wide_500x375.jpg All three pipes should terminate in same location just under the waterline not in varies parts of the sump as it appears

 

[woodnaquanut]

How long do you let it run before removing the end cap? It might take several minutes to stabilize.

You really don't need valves on the open and emergency lines. Since you have them, they should be completely open.

1300+GPH might be pushing the limit of 1" pipe. Do you usually run the siphon valve wide open?

It looks like you have a gate valve on the pump. You might try closing it down a little to see if that's the issue.

It's hard to tell from the pics but the siphon outlet should only be an inch or so below the sump water when it's running. If it's too deep it's hard to get a proper 'flush'.

 

[SGT_York]

I was writing about the 90 on the open channel, but it with the last comment, try closing your siphon more. Sanitary T's help but are not required.

Leave both valves (emergency and open channel) all the way open.

Air gets trapped for a bunch of reason but lack of an outlet is the primary driver. The culprit is the elbows after the valve. they affect the water flow creating pockets of air that stop the water flow, with enough pressure they are flushed into your sump and the siphon starts up. increasing pressure or decreasing the elbows are the solutions. Moving the siphon gate valve to the bottom will solve the issue but you should be able to get a workaround without redoing your pipe. Try closing the valve some more, if that doesn't help try turning up the 90 in the open channel (raising the water level and increasing pressure in the overflow and siphon line) Don't raise it so high that the emergency kicks on.

The results will give better thoughts on how to fix it.

 

[SGT_York]

The open channel airline converts the open channel into a siphon line as an additional failsafe but it alone is not a contributing factor on your siphon line not flowing as it should.

 

[leveldrummer]

your main syphon ends to deep in the water. it should only be 1/2" or so under the water line when running.

 

[jharding08]

My siphon liine terminates about 1" below the water line.

As I said above the picture of the drain lines, I changed out the 90s for 45s, although the 45 that makes it vertical into the sump is what sits almost under water, its the only way I could get the pipes into the sump with 45s.

I'll try to close the siphon valve more, leaving the open channel and emergency whde open

 

[jharding08]

I was writing about the 90 on the open channel, but it with the last comment, try closing your siphon more.

Air gets trapped for a bunch of reason but lack of an outlet is the primary driver. The culprit is the elbows after the valve. they affect the water flow creating pockets of air that stop the water flow, with enough pressure they are flushed into your sump and the siphon starts up. increasing pressure or decreasing the elbows are the solutions. Moving the siphon gate valve to the bottom will solve the issue but you should be able to get a workaround without redoing your pipe. Try closing the valve some more, if that doesn't help try turning up the 90 in the open channel (raising the water level and increasing pressure in the overflow and siphon line) Don't raise it so high that the emergency kicks on.

The results will give better thoughts on how to fix it.

Just to confirm, closing the valve for the siphon drain will increase the pressure in the drain and flush the air out better? This will force more water into the open channel and raise the water level in the overflow.

If that doesnt work, and I turn the open channel 90 up (180 degree turn), then it will be the same height as the emergency, can I turn it 90 degrees or more to get the water level higher without going a full 180?

Where should the water level be in relation to the downturned elbows or is it different per flow and trapped air volume?

 

[jharding08]

One other thing. I turned off my Iwaki because i am going to mod the fan to make it quieter. Right now I have an Aqueon pump running about 750 GPH. Is that not enough to get good pressure in the siphon drain? When I started to "tune", I had the siphon wide open, so it sucked all the water in without using the open channel. I turned the siphon back until the water started to rise up the elbows until it go about to the bend in the 90s. Its quiet, but I need to release the air.

 

[jharding08]

Also, when I get the Iwaki back up, I will be running a manifold of three 1/2" lines to TLF150 reactors with ball valves, so that will take some GPH out of the return exits

 

[SGT_York]

Closing (not closed) the siphon line will raise the water level in the overflow creating more pressure increasing flow to the open channel and increasing pressure on the siphon prior to the gate valve.

Try it in increments slowly turning it waiting 5 minutes then another 1/4 or 1/2 turn until the siphon starts. In this case decreasing the water flow through the siphon to the point the air stoppes getting trapped. There is also the possibility that your siphon line is already past capacity, but the test will give better info if that is the case.

There is no exact water level where it should be it is flow dependent. Redoing your plumbing by increasing the pipe size is the best recommendation but you may be able to find out where the issues are and adjust your current setup.

 

[jharding08]

Closing (not closed) the siphon line will raise the water level in the overflow creating more pressure increasing flow to the open channel and increasing pressure on the siphon prior to the gate valve.

Try it in increments slowly turning it waiting 5 minutes then another 1/4 or 1/2 turn until the siphon starts. In this case decreasing the water flow through the siphon to the point the air stoppes getting trapped. There is also the possibility that your siphon line is already past capacity, but the test will give better info if that is the case.

There is no exact water level where it should be it is flow dependent. Redoing your plumbing by increasing the pipe size is the best recommendation but you may be able to find out where the issues are and adjust your current setup.

When I do start the water back up after feeding, I hear the air being purged into the sump water, then it stops and is quiet as if the siphon started, but after about 30 seconds, more air gets purged. Then it stops, then another 30 seconds. I waited about 7-10 minutes for this to resolve, but it never did.

I do not have the cap sealed on. I need to be able to take it off right now to purge the airso I can get a siphon. It is not threaded, but I know it seals when I put it back on and it starts the siphon

 

[SGT_York]

Are you sure it is air tight? If any air can get into the cap it will prevent your siphon from starting. Typically a pressed on cap will not have a sufficient seal to prevent air from entering the pipe preventing the siphon from starting.

From what you described that seems to be the case.

 

[gt1009]

I agree with SGT YORK. The best way to rid yourself of issues is going to be replumbing with 1.5" pipe. Your water velocity is too high right now for a drain line and is just going to cause you issues down the line.

 

[jharding08]

Are you sure it is air tight? If any air can get into the cap it will prevent your siphon from starting. Typically a pressed on cap will not have a sufficient seal to prevent air from entering the pipe preventing the siphon from starting.

From what you described that seems to be the case.

I agree that not using a threaded cap with teflon tape would lead to air leakage, but then why when I pull it off and then put it back on, it does create the siphon successfully?

My fluid dynamics knowledge has weakened since college :spin3:

 

[BeanAnimal]

The 1" standpipes may be creating some of the issue and there is more than likely an air leak with the press fitted cap.

Lastly, you can drill a few small 1/4" holes in the siphon standpipe just above the normal operating level of the sump. This will allow the air to be purged during startup.

 

[4Hummer]

Couple Things

1: Make the Cap AIR TIGHT. Yes opening the Cap to purge the air is helping you. but you want the full siphon Line AIR TIGHT for it to start automatically

2: Larger Drain Pipes. 1.5"

3: The Drain should be JUST BARLEY under the water. Mine was 1" below the water line and the full siphon would take FOREVER to happen. cut a 1/2 off and now it starts within 20seconds.

4: Make sure the Air bubbles from the standby Drain are not flowing up into the full siphon drain. On my system I had to add a 45 degree elbow to direct the air bubbles away from the Full Siphon Line. were it enters the sump

NICE SUMP