Is this bubble dangerous?

beach bum · 02-26-2002, 06:40 PM

I'm babysitting my roommate's tank for him and while I was adding topoff to the sump I noticed this bubble in the siphon overflow. Looks a little large to me, but then again I no nothing about siphon overflows, does this mean trouble? I would hate to have learn about this in an "emergency" scenario.

Can someone give a little feedback on J-tube husbandry?

beach bum · 02-26-2002, 06:41 PM

these are the lives you'll be saving! "Help us!"

Jimbo · 02-26-2002, 06:47 PM

Hi,

That don't look good. If you have a sump try getting a picher of water and dumping it into the main tank really fast. This may push the bubble out. Try shaking the tube back and forth, some time that will get rid of it. See my thread "jimbo has a reeftank" for info on how to prime them, it can be difficult and may take two people to do.

Have a good day!

nickg · 02-26-2002, 06:51 PM

Hey BB, when I first hooked my overflow up I had a similer bubble in the tube. It proved to the return pump was not strong enough. When I upgraded to a larger pump the bubble was pushed out. Is the return pump kinda weak? You can also try to re-start the siphon, but it's a little tricky and could cause a mess

Rick O · 02-26-2002, 06:55 PM

Try sticking an airline tube up there and sucking it out. I have seen some U tubes retrofitted with a nipple installed at the top and an airline attached and running to the venturi of a powerhead.

Bollox · 02-26-2002, 06:56 PM

Is it possible to put a small hole at the top of the air bubble and attach a small one way air valve.

reefcam · 02-26-2002, 06:58 PM

It can turn into a potential problem. This all depends on his flow rate. The bubble restricts the amount of water that can move through the tube.

To remove the bubble, IME, if there is enough water flow, you can quickly move the tube up and down, but make sure that both ends do not leave the water. This will help the water move out of the tube. If you are having trouble, another method:

Let me see how I can explain this. You need to restrict the water flow through the U-tube (or J). How I have done this is to tip the tube into the surface skimmer box to restrict water flow. THere should still be a little flow. WHen the water level reaches close to the top, tip the U-tube back to normal to allow water to flow normally again.

Since the water pressure is now a bit higher in the tank, the water flow through the tube should increase and help push the bubble down the tube and out the back. Sometimes this doesn't work due to the bubble, then you may need to do a combination of method 1 and 2 to remove it.

Just got done doing this last weekend.

E-mail me if you are still having problem. The other method is to run an airline through the tube and suck out the air.

Big Dave · 02-26-2002, 06:59 PM

OH MAN!!! Would you look at the teeth on that puffer!! Reminds me of my clown trigger I used to have. Couldn't clean my tank without bleeding so he had to go!

If you have a small power head you can direct it into the tube and that should flush the air bubble out. The air bubble will slow down the siphon, just like squeezing a flexible tube. The idea of a larger pump should help correct it from happening again too. HTH

-Big Dave

beach bum · 02-26-2002, 07:22 PM

You guys are the s***! Thanks for the quick replies. Reefcam, I tried the tipping thing first, but gave up and tried the "quickly up and down" thing, and that did the trick. The bubble just kind of shook out in pieces until it was all gone!

The return pump is a Mag7. Is more power better? I think its a 1" overflow tube.

He's got a half of a water bottle in the outside the tank portion of the overflow box, which is why I was able to shake it rather aggressively without exposing the tube ends.

half a water bottle:

glassman · 02-26-2002, 10:03 PM

ive got a similar overflow box on my 55. it doesn't seem like the syphon can keep up with the mag 9.5 pump ive got going. it's got 4 feet of hose leading back to the tank, and some of it is diverted to a protein skimmer. i tried adding a 2nd and 3rd syphon tube hoping this would allow it to keep up, but to no avail. i finally had to install a ball valve and hinder the flow out of the pump. its so upsetting to know that my pump isn't running at full capacity. im sure the tank could benefit from that turnover. does anyone have any suggestions, or am i missing something fundamental in the simple physics of the matter?

Doug1 · 02-26-2002, 10:19 PM

Glass man for what its worth I have both built that style overflow and used the Amiracle with the one inch drain fitting, The U tube seems to max out somewhere around 400 gph. If you look at the higher flow rated Lifereefs or the CPR hang on over flows you will notice they use larger diameter drains or multiple drain fittings. You could try to find the set of fittings in !.5" and see if there is room in the box to fit that in or add anothe r 1" hole and fitting to increase the drain rate.
Beach Bum I think the mag 7 is about right, chances are it caught a few srtay bubbles, looking for those is a daily maint thing with that type of overflow

All in all tho once dialed in they are not as bad as people make them out to be.
ps the ailine tube is the quickest way I found to remove the bubbles

glassman · 02-26-2002, 10:35 PM

so are you saying that it's the u tube maxing out at 400gph that is the restricting factor or drain tubes needing an upgrade? just looking at the drain tube while in operation, it sure appears as if it should be able to handle more flow. that is why i thought that the u tube was the culprit. of course, 2 and 3 u tubes didn't solve anything so. . .

Jimbo · 02-26-2002, 11:58 PM

Here's my setup

Overflow that big dave sold me. I'm using 1" inch inner diameter hose to bring the water to the sump. I'm running the skimmer and return off of a rio 2500. I am using the valve that came with the rio to restrict what the skimmer gets. My u joint has np cleary out small bubbles.

Here's a pic of my overflow. I

Here's a pic of the 1/2 tubing I inserted into the overflow hose to feed the refugium. In the upper right you can see the bulkhead connector that returns water to the sump from the refugium. I only have one pump

I made a mess taking this picture just laugh all you want

Have a great evening!

reefcam · 02-27-2002, 02:56 AM

Beach bum, glad you got the bubble out. Adding additional tub may or may not increase your flow rate out of your skimmer box and into the overflow box, but you have to also realize that have 2 - 1" tubes can help with better flow rate, but your bottle neck (or restriction) will be at the point where the overflow box drains. So you will also need to increase that portion. I have a Iwaki 30RLT and have to turn it back to prevent overflowing.

MikeP · 02-27-2002, 07:32 PM

I have had the same problem, It has to do with the way you start the syphon, if there is a gap of air in the tube when you start the syphon this will happen. Eventually when you water get s low in the tank the syphon wil virtually stop and cause an overflow in your tank. I have had my tank overflow twice because of it. Keep an eye on it if it happens again. I didn't.

Is this bubble dangerous?

similar overflow box

I couldn't resist