Overflow siphon lost

[zbrook1]

Okay...I have a Eshopps PF-1200 overflow with two 1 inch bulkheads and two 1 inch U-tupes on a 75 with 20 gal sump. Im runnig it through a dry run(just fresh water) to make sure everything is okay before I add expensive salt. My problem is one of the U-tubes after a while of running seems to gather bubbles at the top and slowly loses siphon leaving only one to do most of the work. Will this change with salt water do to surface tension of the water? The U-tube is air tight.(no pin holes or such) and both ends are in the water the same length as the other.

 

[sjm817]

How much flow do you have? If one U Tube will handle all the flow, you are better off running it that way.

 

[harrisagogetter]

What size tank so you have? Maybe you could just drill it and get a reef ready. buy a mega-flow and go from there. After having one I would never use anything else.

 

[sjm817]

You dont need to go through all that. You can run a HOB overflow perfectly reliably as long as it is set up correctly.

 

[datablitz]

it sounds like you dont have enough flow for that overflow, you should either try using a larger return pump, or taking one of the tubes out. you want to have enough flow through the tunes that air bubbles get sucked all the way through. you usually want 500-600 gph per tube. i have a mag12 running a tank with a dual tube overflow, and it works perfectly.

 

[down and outman]

Before you go drilling a tank make sure it's not tempered! LOL! I thought only the bottom was tempered on a 55 I tried drilling. BOOM. that's why I upgraded to a 90 Reef Ready.

 

[zbrook1]

Thanks folks.....Im sorry I forgot to mention that the return pump is a Mag 9.5 but there is a ball valve in the return line that I closed slightly to reduce the flow(wide open seemed to be too much)...the 9.5 is just a little much for this tank I think(thanks to LFS advice) But I am using only one U-tube at this reduced flow and it seems to be working fine so far. Im sure that was the problem...not enough flow through the overflow.

 

[datablitz]

glad to hear you got it working better.