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View Full Version : U-Tube Overflow Flow?


luke33
02/01/2007, 10:31 AM
I have a hurricane overflow, and its rated at 1200gph. Like many know, its not going to push this much flow with the two u-tubes they give you. So i moded it and have 4 u-tubes flowing 1200gph. I figure, well if it fails in one u-tube, i've still got three, so i won't flood(no failes yet). I was just wondering if anyone else has added more than the stocked u-tube's in there overflow, and if there was something wrong with doing this? Its been working for months perfect, so far so good!

sjm817
02/01/2007, 10:40 AM
It can cause problems in a "normal flow" application.

Lets say you have a system with 350 GPH of flow. A single U Tube will handle it fine and there is plenty of velocity to keep the bubbles pushed through. Now add a 2nd U Tube. You cut the flow through each U Tube in 1/2. Now you are at 175 GPH in each tube and will have bubble accumulation issues. You always want a good strong flow through the U Tube.

I've seen posts where people added a 2nd tube for redundancy, which actually caused a problem instead of fixing one.

As long as the U Tubes have enough flow through then to keep bubbles clear, its OK.

luke33
02/01/2007, 10:43 AM
Yea, i understand, but for mine, it would be fine right. If you added more to a lifereef, then it would overflow and couldn't take that much flow, but for a inferior design like mine, or a ebay utube, i bet it would work well. And i hope i dont get someone on here say....why do you need that much flow 3-5x bla bla bla(no offence)

luke33
02/01/2007, 10:45 AM
And there is plenty of flow, no bubbles accumulating at all, made sure of that : ) Wife would kill me if there was a flood in the house

sjm817
02/01/2007, 10:45 AM
Actually, there is a guy who put 4 tubes in a LR and is running some insane flow through it. The post was on the DIY forum. I'll see if I can find it.....if I could only search...

luke33
02/01/2007, 10:51 AM
No kidding. Well i'm happy with 1200gph, but by the looks of the drains i know i could push 1500-1600 through it. There's just no reason to, just curious if anyone else had done this and for how long....and most importantly if it was safe. I couldn't think of any negative's

sjm817
02/01/2007, 10:54 AM
He was pushing like 2200 - 2400 GPH?? through it. Crazy. Its a cool setup. I'll try the search later.

luke33
02/01/2007, 10:56 AM
UNBELIEVABLE.........I think i'd have to be one of those persons to ask why? Maybe that was all his flow for his tank. And he must not have liked powerheads and so on in his tank. I wonder how the skimmer did with that much flow?

jefathome
02/01/2007, 11:05 AM
<a href=showthread.php?s=&postid=9132164#post9132164 target=_blank>Originally posted</a> by luke33
Yea, i understand, but for mine, it would be fine right. If you added more to a lifereef, then it would overflow and couldn't take that much flow, but for a inferior design like mine, or a ebay utube, i bet it would work well. And i hope i dont get someone on here say....why do you need that much flow 3-5x bla bla bla(no offence)

The total flow through the U-tubes will only equal the flow of water from your sump back up to the tank. If it is going through 1 tube, the flow in that tube is equal to the return flow. Through two tubes, it is half... and so on.

As far as overflowing your siphon overflow, it will only overflow if the capacity of the Utubes (AND the return flow from the sump) is more than the drain in the overflow can handle. Adding more Utubes will not overflow the overflow unless the return flow is too high.

If your Utube can handle say 600 GPH, your drain can handle 1200, and your return is over 600gph (say 800gph) then the tank will overflow, not the overflow. In this case, adding another utube WOULD be beneficial and the total flow through each would be 400gph.

You want the flow in each tube to be as close to max as possible (say 90% of capacity) so that the bubbles will get pushed through.

NACLH2OFOOL
02/01/2007, 11:19 AM
I've been running 4 of them on my 120 for over a year now with no problems. Since I currently have to divert some of my return flow back to the sump, I plan on adding a 5th in order to max out the flow. HTH

merk1_99
02/01/2007, 11:24 AM
I've notice among my friends. All the U-Tube overflows that flooded were because of poor maintenance/cleaning. I ran a U-Tube for 2 yrs no problems. I always kept a second tube on hand to swap out when I need to clean the other tube....

luke33
02/01/2007, 12:19 PM
Yea my over flow says 1200gph, and my return pump with head loss was throttled back to 600gph cuz the overflow couldn't keep up with anything more. I was disapointed, but didn't expect 1200gph. So i got 2 more utube's and turn'd my pump on full force and its been perfect for a few months now at 1200gph with 4 tubes. I"m guessing the cheaper utube model's on ebay would do the same as this one. Thanks for the feedback!

sjm817
02/01/2007, 12:30 PM
2000 GPH Lifereef (http://reefcentral.com/forums/showthread.php?s=&threadid=672249)

http://reefcentral.com/gallery/data/586/638743__DSC01822-_web_-.jpg

luke33
02/01/2007, 01:06 PM
That is pretty cool thread. Yea, mine is definately quieter with more flow, i may try a few of these other mods and see what happens.

megaspoot
02/01/2007, 03:46 PM
are the tubeless designs much worse? ie. the CPR overflows. If they are coupled with a venturi capable powerhead will the problem of siphon loss be eradicated?

sjm817
02/01/2007, 03:49 PM
Proper flow through a U Tube is the only way to have a reliable siphon. A CPR depends on an external pump to constantly remove accumulated air. Not a reliable design.