[Rob]

After nine months or so, the custom sump and syphone overflow box constructed by Scott Reefland has been running great. Just a few tweeking and technology questions... I need to find out if anyone has improved syphon tubes!

The two syphon tubes can keep up with the main pump, but only just. If one catches bubbles or gets a little restricted with hair algae, water level in the main tank starts rising! I've come home to a few near-floods...

Any suggestions here? A third syphon tube? Tried a temporary one made of 1" plastic hose, and the flow in all three slowed down enough that bubbles began to accumulate in all three tubes!

One of my big worries is that I'm the only person in the house that can restart a syphon tube. It's tricky, with an airline in my mouth, sometimes getting a mouthful of tasty salt water. The lady that takes care of my fish while I'm away wouldn't be able to do it, if necessary. Once I had to drop everything at work and run home.

I had an idea about a syphon tube with a bleeder on the top. Connecting an airline to a valve on top, and sucking, should start the syphon a lot quicker and easier than the current method.

To extend this, the airline can be connected permanently to a vacuum source, like the venturi air hook-up on an existing powerhead inside the tank. I wonder if anybody has tried this. When I get a minute today or tomorrow, I'm going to try posting this to Reefland, and see what solutions others have tried, as in:

http://www.reefcentral.com/vbulletin...001/06/4/27043 (lots of ideas but no clear solutions!)

The best comment was:

If you don't push enough flow through the tubes, you will accumlate air bubbles and that will cause a siphon to stop. Overflows that incorporate multiple u-tubes are not as susceptible to this because typically one tube will stop, but the other tube(s) will still have enough capacity to continue siphoning. You can further tweak an overflow by using smaller or larger diameter u-tubes to get the desired flow rate for reliable performance.

Thoughts?

[naser]

i have seen the version where you have some sort of bleeder t-d off a power head so it sucks all the air out all the time.

[fishpoo]

i owned a CPR continuous overflow at one time and a power head was used as you describe.
I also setup a U tube overflow with a nipple on the top of the u tube. The hose was left on and to start you suck the hose and pinch it, then place the end in your sump, or connect to ph or plug. works.

[Randy]

I think pictures are worth a 1000 words so here it goes:







I used a ZooMed Power Sweep as my power head. It happens to oscillate from side to side to create a wave motion. They tend to lock up from time to time, but I like them. I have had this mod in place for at least 3 weeks and it works flawlessly. Just make sure that you have absolutely no leaks where you attach the hose to the U tube.

The power head creates suction like a venturi. If the power goes out no big deal everything sits at a stand still ~ power kick back on and everything continues as normal (as long as you have not leaks).

[johnny gray]

why don't you drill your tank drain your tank down enough so you can silicone in the over flow box figure out where to drill the hole put duck tape on the in side to prevent glass getting in it drill /silicone in your over flow plum in to the sump and don't wirier about it again