syphon U- tubes

[purge43]

It looks like the majority of everybody seems to use syphon tubes, or overflows of some type. My system is designed for use with the finger box in the tank and a U tube filling up an outside gravity down flow box. my unit came with a small piece of air tubing and i concluded that is used to start the syphon action, by inserting it up in the tube while both ends are submerged , then suck on the line to fill up the u tube and establish a syphon. imo thats crazy, not to metnion i alwyas get a mouth full of sea water.With the advancements in technology there has to be a better way . How do most of you guys start the syphon action , with this same methods I described above? I do find it easier if i use a 6 or 7 foot piece, then the water accumulates in the line long enuff so i dont taste the water. any ideas are appreciated,

[gnorts]

I used the way mention above. Ive only done it once since i set my tank up in november. THere are other ways one being an "aqualifter" That involve you making a hole in the u-tube at its highest point and inserting air line hosing. Then the aqualifter sucks out the air for you. Its good to have I just havnt gotten one yet.

[oldsaltman]

I leave an airline in mine 24/7 and it is connected to an aqualifter. It maintains my syphon and restarts it if I turn it off for cleaning etc. ;)

[sjm817]

Some people fill the U Tube, cover the ends, then quickly turn it over and put it in. When I ran one, I'd use an Aqualifter to pull out the air, then removed the airline once started since it was no longer needed.

[jus10kase]

I use the method you mentioned. I`ve had some tubes seem to work better than others, and sometimes a certain end one way or other. I usually do have to restart it now and then cause some air does build up slowly.

[oldsaltman]

Over a period of weeks my "U" tube has always developed air in the top of it which slows down the flow. I leave the airline in it hooked up to the Aqualifter because that solved the problem. No more air gets in, and if it does the Aqualifter pulls it right out. ;)
Then when I clean the overflow and "U" tube I don't have any trouble restarting it. :D

[Toddrtrex]

<a href=showthread.php?s=&postid=14456672#post14456672 target=_blank>Originally posted</a> by oldsaltman
Over a period of weeks my "U" tube has always developed air in the top of it which slows down the flow. I leave the airline in it hooked up to the Aqualifter because that solved the problem. No more air gets in, and if it does the Aqualifter pulls it right out. ;)
Then when I clean the overflow and "U" tube I don't have any trouble restarting it. :D

If that was happening there wasn't enough flow running through it. A quality U-tube over flow box shouldn't need to have an aqualifter hooked up to it. In fact that takes away one of the benefits of it. I have a LifeReef overflow on my 75 and never have air bubbles collecting in it.

Whenever I clean out the U-Tube I do have to restart the siphon with an air line, but if you use a long enough one you won't get any salt water in your mouth.

[thegrun]

I drilled a hole in the top of the U bend and glued in a 1/4" barb that I attached a 18" length of 1/4 " tube to with a plug for the end. Place the U bend in the water, open the 1/4" tube and the U bend will will with water to near the top. Suck the remaining air out of the U bend. You can then fold the 1/4" tube over and pinch it while installing the plug back into the tube. Never get a mouth full of water again!

[oldsaltman]

<a href=showthread.php?s=&postid=14456860#post14456860 target=_blank>Originally posted</a> by Toddrtrex
If that was happening there wasn't enough flow running through it. A quality U-tube over flow box shouldn't need to have an aqualifter hooked up to it. In fact that takes away one of the benefits of it. I have a LifeReef overflow on my 75 and never have air bubbles collecting in it.

Whenever I clean out the U-Tube I do have to restart the siphon with an air line, but if you use a long enough one you won't get any salt water in your mouth.

You may be right, but I have read a number of post with similar problems. The only "U" tube I have experience with is the one I have used for the past 3-4 years. What I posted works for me and would work for anyone with the same problem. Just like the above post by "jus10kase". :D

[cdbias2]

You can hook the airline tubing to the air intake of a MJ powerhead and leave it there.

[Jaded_Falcon]

I had the air bubble problems in my u tube constantly. I was sucking out air every day. Then I did some reading on here. Increased my flow as was already suggested. Now I can't get air to stay in there if I try! (did it just to see. Helps me sleep knowing it's not an issue.) Don't knock it till you try it! I'm sure aqualifters work, but it's one more thing that could fail.

[oldsaltman]

The good thing is that I only have a few more weeks to worry about my "U" tube. My new tank is drilled and should be ready for all my fish soon. NO "U" TUBE! :D

[jbird69]

<a href=showthread.php?s=&postid=14461001#post14461001 target=_blank>Originally posted</a> by Jaded_Falcon
I had the air bubble problems in my u tube constantly. I was sucking out air every day. Then I did some reading on here. Increased my flow as was already suggested. Now I can't get air to stay in there if I try! (did it just to see. Helps me sleep knowing it's not an issue.) Don't knock it till you try it! I'm sure aqualifters work, but it's one more thing that could fail.

Yep

After I clean my utubes every couple months, I have to restart the syphon. I never seem to be able to suck all the air out, but as soon as things get circulating again, you can watch the bubble get pushed right out. Im talking bubbles the size of a large grape or golfball...pushes right out.

[sjm817]

<a href=showthread.php?s=&postid=14461001#post14461001 target=_blank>Originally posted</a> by Jaded_Falcon
I had the air bubble problems in my u tube constantly. I was sucking out air every day. Then I did some reading on here. Increased my flow as was already suggested. Now I can't get air to stay in there if I try! (did it just to see. Helps me sleep knowing it's not an issue.) Don't knock it till you try it! I'm sure aqualifters work, but it's one more thing that could fail.
You fixed it the correct way. Using a vacuum pump in the U Tube or via a fitting in the top of the U Tube is the wrong way and is not a reliable fix.

[oldsaltman]

<a href=showthread.php?s=&postid=14465099#post14465099 target=_blank>Originally posted</a> by sjm817
You fixed it the correct way. Using a vacuum pump in the U Tube or via a fitting in the top of the U Tube is the wrong way and is not a reliable fix.

It may not be reliable in your opinion, but is is a safety issue for me and has worked will for several years. It is reliable in my opinion. ;) If the power fails, or the Aqualifter fails it doesn't affect the "U" operation. It is a simple backup to insure that my tube stays bubble free. :cool: You may say it is not necessary, but you can't say it is "not reliable".

[sjm817]

Fair enough. Its not reliable "in my opinion" :)

In any case, it is not the way the device was designed to operate. The design is the flow through the U Tube keeps the bubbles from accumulating. People have trouble with these overflows all the time and can get them working well by simply running them the way they were intended to be operated.

[KarlBob]

Getting tank water in your mouth is not a good idea. Instead of applying suction by mouth, you might want to try a turkey baster with a narrow tip. It can be tricky, but it's far more sanitary.

Bubbles used to build up in my overflow U tube until they cut off the syphon. Now I use a smaller-diameter U tube, and I have no problem.

[sjm817]

The smaller diameter U Tube is also a good fix for lower flow systems.

[oldsaltman]

I wonder how many people would agree that their "U" tube works perfectly 24/7 as designed without any problems vs. those that have problems with air in them? Like I said before I fixed that problem with a drilled tank.:rolleyes:

[Toddrtrex]

6+ years with a LifeReef overflow box, has worked perfectly the whole time I have had it. (( Using it as designed, didn't attach anything to it, which would defeat the purpose of it ))

[sjm817]

I ran one for ~ 4 years with never a single issue. I have a friend who has ran one for ~ 6 years. No problem. I've seen plenty of posts on RC of people with similar posts. If it is a well designed unit and set up properly, it will never accumulate air. It will run indefinitely without an issue. There is no need to add anything to fix a problem that isn't there.

[oldsaltman]

<a href=showthread.php?s=&postid=14466083#post14466083 target=_blank>Originally posted</a> by sjm817
I ran one for ~ 4 years with never a single issue. I have a friend who has ran one for ~ 6 years. No problem. I've seen plenty of posts on RC of people with similar posts. If it is a well designed unit and set up properly, it will never accumulate air. It will run indefinitely without an issue. There is no need to add anything to fix a problem that isn't there.
That is great, and I am glad that is works for you! I just don't remember a lot of post about how happy everyone was with their "U" tubes.

[GunnerO]

Ah, Increasing flow... to fix the air bubble problem. I've had constant problems with air getting into the U-tube.

Can you increase the flow but lowering the collection box inside the tank before the U-tube sucks it up? Thanks.

[jus10kase]

It`d be nice if someone explained HOW to increase flow.

[oldsaltman]

<a href=showthread.php?s=&postid=14467371#post14467371 target=_blank>Originally posted</a> by jus10kase
It`d be nice if someone explained HOW to increase flow.
I guess you just keep buying bigger pumps until the "U" tube works. :confused:

[Toddrtrex]

<a href=showthread.php?s=&postid=14467446#post14467446 target=_blank>Originally posted</a> by oldsaltman
I guess you just keep buying bigger pumps until the "U" tube works. :confused:

Just start off with a properly sized pump for the U-tube to begin with and won't have the issue.


<a href=showthread.php?s=&postid=14467371#post14467371 target=_blank>Originally posted</a> by jus10kase
It`d be nice if someone explained HOW to increase flow.

There are two ways, smaller diameter U-tube, or more flow from the return pump. If you have a ball valve on the return side, open it more.

Lower/raising the box (( the one inside the tank )) will just effect the level of the water inside the tank, and won't effect the flow.

[sjm817]

Its amazing how something so simple can be so misunderstood.

U Tubes work off a very simple siphon principle. Nothing new here. The problem is water flowing over a weir carries bubbles with it. If there isn't adequate flow through the U Tube, they can accumulate in the apex. Have enough flow, they dont.

There are other factors, Not all U Tube overflows are created equal. Some are designed very well, some are not. Because of the design differences, some are more susceptible to air accumulation than others. A U Tube overflow that would require an external vacuum pump to remove air would be a very poor unit.

How much flow is needed? The typical overflow with a 1" U Tube needs about 200 GPH minimum to keep bubbles pushed through. Not a ton of flow. A Mag3 can do it with typical head. An overflow with a smaller U Tube like 3/4" will need less.

How to increase flow? If the pump is too small, use a bigger one. Often, people use inadequate pluming. Just using a better plumbing setup will often fix the issue.

Again, use decent equipment and set it up properly and it works as designed. No different than anything else. There is always the option of a work around fix instead, but its not difficult to do it the right to begin with.

[sjm817]

<a href=showthread.php?s=&postid=14467169#post14467169 target=_blank>Originally posted</a> by GunnerO
Ah, Increasing flow... to fix the air bubble problem. I've had constant problems with air getting into the U-tube.

Can you increase the flow but lowering the collection box inside the tank before the U-tube sucks it up? Thanks.
Actually raising the box up helps some. The height of the box has no effect on GPH. That is controlled by the return pump.

A siphon works by the difference between the high side and the low side of the levels. In an aquarium overflow, that is the skimmer box and the drain box. The greater the distance between the high side and low side, the stronger the siphon. This is what I was meant by not all overflows are created equal. Some such as the Lifereef pay better attention to this than others and is why they work so well.

To adjust your overflow, raise the skimmer box up if you can. On the drain side, sometimes depending on the setup, you can tweak that a bit. If it uses a standpipe, have it high enough to keep the U Tube submerged, but no higher.

If you need more flow, how is your pump plumbed? The type and diameter of the tubing, hose barbs, elbows, etc all have an effect.

[jbird69]

If your water is entering your overflow box with lots of turbulance, you will get lots of bubbles passing thru your u tubes. As u tubes build up with algae the flow will become restricted. If you get good amounts of hair algae in the u tubes, they can start to snag bubbles. This combination can potentially lead to your DT slowly overflowing. The teeth, or critter stop you put on the rim of your box can create turbulence. Its a good idea to do something to smooth out the flow into your overflow box if its turbulent or splashy. And its really important to not let too much algae build up in the u tubes. I keep meaning to build a shade for mine to protect it fro my MH lighting. this will make a huge difference in how often you need to deucsh out your u tubes.
A correctly designed external overflow with utubes is foolproof, but it is definitly not mainanance free.

[sjm817]

Good points. I had a little shade over mine to keep the (T5) light out. I would clean out the U Tube every few months. It would get brown slime in it. Also on the turbulence going over the weir. A smooth toothless weir would work best. Still, bubbles will get in the U Tube. Adequate flow will keep them from accumulating.

Here is an old pic I found from 2005. Nice and clean!

http://reefcentral.com/gallery/data/500/71647PICT1489.jpg