HOB Overflow Standpipes help!

I just have a question for those with HOB Overflows.
Right now in running 2 stock and in my overflow box. I cannot seem for the life of me to get them to run without any issues. Every other day or every day I have to adjust them so that I can keep the wl in the dt at the same height. I am constantly battling with them starting to siphon no matter how I adjust the outer guard or the airlines. I it's not that they don't pull enough water an the wl in the dt begins to rise. I get it going good for a day or so and then I have to adjust it again I am getting extremely frustrated with it. I do not have enough room to run dursos and I am looking for an alternative. I cannot drill at this point and I'm at my wits end. Please any suggestions are appreciated.
I have to go on a job next week and am not comfortable leaving this for a week.
Thank you for your help.

 

If you don't have room for Durso standpipes, look into Stockman mods...they don't have the "T" sticking out of the side.

You may need to dial back your return pump a bit, which might help "match" the return flow to what's draining from the tank, at least in the meantime. However, I suspect getting the standpipes dialed-in (meaning the venting) will help a lot.

Are you running a CPR-type overflow, or a U-tube type? If it's the former, are you running an "aqualifter" pump on it to maintain the siphon?

 

Hey Greg, you've helped me before with the same issue.




I took those right now.
No T.
U tubes need to e soaked but they are clean.
I am doing a wc today so I will mess with the flow rate from the return. The only thing is when the flow Is to low I get air bubble in the u tubes.
I have messed with this for so long I'm about to loose my mind. Just looking for guidance. Maybe something I'm missing.

Thanks again Greg.

 

I know someone who just had a similar problem with a built-in overflow, but their trouble was a bad seal, so the level in the overflow varied, which made the standpipe siphon unstable.

From what I can see, I'd have to say that the venting of the standpipes is the issue. Are the vents wide open?

 

One of them is wide open and the other is about 1/4 to 1/8 closed. I can't seem to sync them. Should I pull the shield all the way open and then play with the vent tubes to try to sync them that way?

 

Dan, I have a DIY style overflow, it's an Intank overflow like a surface skimming reef ready, but it relies on a DIY HOB overflow to get the water from the intank part to the sump- via a siphon style OF. the HOB part is 1.5 inches ID.

I NEVER have to mess with mine. I AM trying to help YOU figure this out.

All I thought of when looking at your pics, was that both of the air vents that size should be open? this causes air bubbles to capture in the U tubes? I don't think you can run them similar to a Bean sytle, different style of siphons totally- they don't go have to pull water over the DT level.

When I was researching, building, one thing I know for sure is that if you have to have 2 U tubes for the flow rate, or else- puddles- then I understand.

But, When you have 2- the flow is reduced in both and bubbles get caught w/o flowing thru with the higher velocity of just one tube- you knew that right?
IMEHO- 2 U tubes is actually NOT as got as 1, and causes them both to fail easier b/c of letting the bubbles form and slowing/stippin siphon with the lower velocity.

Have you tried just one tube? 1" is supposed to flow like 600+ GPH I thought?

Good luck,
Todd

 

Have you experimented with how far you insert the air tubing down into the caps? I know with my Stockman how far the airline is inserted makes a huge difference in flow. It seems like it works best when the end of the tube inserted in the cap is about equal to the water surface in the overflow box but I sometimes raise or lower the airline a bit to increase or decrease flow and quiet the overflow. I have a single 1" Stockman and the airline has no valve or restriction on the free end.

 

Todd, I think I might not be understanding you completely. I remember the way yours is and I like it. Not possible to do mine like your though.

Both my air vents should be open? Is that what your saying? The only time I get air bubbles is when I reduce the flow rate from the return and there isn't enough flow through the u tubes.

Honestly I haven't tried just 1. The reason I haven't is because I don't think that just 600 gph is enough flow rate for my system. Do you disagree?

Let me know if I don't answer all your ?s

I have tried and both vents are right below the holes in the standpipes. It seems to work best but I guess that's not working for me is it.

I can try to adjust it some more.

 

So I just opened the vent pipe valve all the way. I pulled the vent tube up right above the holes in the standpipe to about the water level in the overflow box and it seems to be ok at the moment. I don't know how long it will last but I have several days to play with it before I'm gone for a week.
All your help and troubleshooting is very appreciated.
Thanks everybody. Anything else you think I might be doing wrong? I will post a video as soon as I can load it.

 

I think he is asking have you tried to close the vents up some, in order to get less air in. If you get to many air bubbles it can break the siphon. I would start by restricting the air vents, I have a small hole in mine about the size of a pen tip head.

Do you have a gate or ball valve on your return line? If you do you can restrict the flow going back into the tank until it is where it needs to be for the drain pipe.

Also I saw greg asked if you had an aqua lifter and did not see if you said you did, if you don't this could be a good piece to get. This will insure that you will always have a siphon and won't have to worry about it losing it's siphon due to air bubbles.

I modeled my hob overflow after Todd's, he helped me quite a bit with mine. You said you don't have enough room in your tank for this style setup, is it that you can't fit a stand pipe in your tank? I am running a 2.5" stand pipe in my 55 and it really doesn't look that bad, and soon it will be covered in coraline.