Tuning the bean overflow...

[pdiehm]

Good news is, the overflow works. I had it tuned with my home depot flo-tech return pump until I could rig up a return for my sicce pump that i'll be using for the display.

Bad news is, I'm having extreme difficulty tuning this with the sicce pump. Odds are it's something extremely simple, it's not funny.

Here's what's going on.

At start up, the water level never goes over the emergency elbow, always stops short...not a bad thing I guess. Water goes down my main siphon and my open channel. Good. Problem is, if I adjust the open channel to where it's a trickle at full operation, and cover up the air tube, it doesn't start to siphon. That's not good.

While in operation, I hear the water running down both drains, more so the main siphon than the open. Leads me to believe there's air going in there somewhere. Both drains are about 1" below water surface. I used thread sealant for the caps, but I can't get them off...I put them on real good. I guess I need to go get a pipe wrench or something.

Once it settles down, takes about 30 minutes, it's real quiet. though I have a good amount of little bubbles from the main siphon, not a tremendous amount, but some.

Quick Caveat: I do NOT have the drain tubes going from the final elbow to the water in the sump sealed in. I'm afraid to seal them because if I do, and I gotta change something I'm not entirely sure how to do that once pvc is cemented together.

 

[freakit]

The full siphon pipe is the one that should be adjusted not the open channel... The full siphon pipe is the one with the gate/ball valve.

I have my last fitting going into sump unglued. No air bubbles make it into the full siphon pipe.

 

[pdiehm]

I only have a gate valve on the full siphon. I am uploading a video. You can hear the noise that I'm talking about. Also show you the trickle out of the open channel.

I'm not far off, I know that much. I'm fairly sure there's air in there, I just don't know where it's coming from though. I may run a bead of silicone around each joint before I try to take off the threaded cap (though I'm fairly positive it's coming from there).

http://www.youtube.com/watch?v=J1YLwaLIgio

 

[pdiehm]

almost an hour later, and that gurgling sound is gone. Now you can easily hear the water running down the open channel drain. Does that mean the flow is too high through it?

 

[freakit]

almost an hour later, and that gurgling sound is gone. Now you can easily hear the water running down the open channel drain. Does that mean the flow is too high through it?

Correct.

 

[saltyhog]

To tune mine I opened the full siphon all the way (it should not have any, ZERO bubbles) and slowly closed it 1/4 turn at a time until there was just enough flow to have a very few bubbles in the open standpipe. There should be no noise whatsoever from the open standpipe. If you can hear it it's not right. My emergency drain is also never wet with a restart.

 

[pdiehm]

So I found part of the reason my main drain won't go to a full siphon...I took the support clamp off and saw water. Where I glued the gate valve to the 1.5" pvc pipe there is a gap that's about 1/4" long.

I don't want to take it apart as the gate valve was $45. Is it as easy as running a silicone bead around that junction? Or do I run some pvc cement there (I assume this isn't a great option)?

 

[pdiehm]

I'm extremely frustrated with this. So much so that I'm really toying with selling it and getting a reef ready tank.

I have a leak, I don't know where it is. I can rebuild the drain, but the issue is, everything is cemented in and if I understand correctly, that means, cutting the bulkhead, and removing the overflow box.

Very very frustrated. Probably spent 10 hours today trying to tune this in, and once it gets going (takes about an hour for the air to fully purge) it's really nice. The problem is, it doesn't start back up and pick up where it left off. Did I mention that I'm frustrated?

 

[hybridazn]

Mine occasionally doesn't start back up either. If it doesn't I just simply put an air tube up the full siphon tube and suck on it to start the siphon.

 

[Thunderfan]

I was going to use all slip/slip fittings on mine. Your issues have made me lean towards putting some threaded ones in there in case I have to take it apart. Although I wonder if the joints where glued together all the way if you would be having these problems. Can you post some pics of your set up? May help someone catch something you might have overlooked.

 

[pdiehm]

So, I after taking off my 3/4" garden hose, and attaching 1" pvc pipe to my return pump...I am happy to say, the system works. It works
fast, and it works silently.

The problem wasn't an air leak. It wasn't something I did wrong. It was something that I didn't know about (and no one even thought to ask that question). The 3/4" tubing restricted the flow, it was really low, so i had to adjust the gate valve virtually closed. Physics dictates that it cannot start a siphon with such low pressure. Once I changed out to the 1" PVC pipe, which reminded me why I do this in the garage...the pvc exploded apart because I didn't fit it tight enough, water everywhere. Quite cold. Anyhows, once I changed to the 1" pvc, the emergency kicked in, and the main siphon started within a minute or so, and did a full purge of the air within another 30-45 seconds.

At such low flow with 3/4" tubing, the full siphon would occur, but it takes 40 minutes. Took 12, almost 13 minutes for the full siphon to kick in, and another 20 minutes or so for the final air purge. It was told to me that I have a leak, which didn't make sense, because it would air purge, and if I had a leak, you would think that there would not be an air purge.

I can now start working on the return plumbing. I have decided to split the returns so there's one on each side of the overflow. There'll also be a T feeding a refugium, with very very slow flow.