Does anyone have a picture or schematics of this overflow box? Supposely the siphon never breaks like that of the CPR.

Rico.

Never mind!!! I found... Now does anyone know how it works?

Rico,

I have two knock offs of this design in my tank, and they do not break the siphon when the power goes out. If you look carefully at the outside box that has the bulkhead in it, in between the bulkhead and the J tube you see a partition. When the power goes out the box will drain the entire left side of this box, but the right will only drain down to the partition. This leaves the tube submerged and the siphon stays intact. I may mistaken but I think the key to this is that the partition level is higher than the bottom of the J tube that is in the tank, so that the overflow box only drains to this point also. I think if you did not have this partition you could use the Durso standpipe (w/ Ken Stockman influence) and have the drain holes higher than the tube again keeping the siphon. HTH.
Scott

I must be a real idiot because I can't figure it out. Shadetree thanks for your response. I see everything that you are saying. What I am thinking is that in a case of a power outage the U tube will continue to siphon until the water level inside the box that is inside the aquarium gets to the bottom off the time where it will suck air and the siphon will break. When the power comes back on, I do not see how the siphon will start up again unless the U tube is primed again.

Rico.

Remember the partition. It is higher than both ends of the 'U' tube. If the inside box were to siphon until it sucks air, then it would be siphoning uphill. The siphoning will stop when the inside and outside box are at equalibrium.

I think I got it.. Thanks guy... Off I go to buy some acrylic! [img]/ubb/smile.gif[/img] Any good suggestions on how to bend the tube into a U tube?

If your building one cuz your crafty fine but if your building one to save $$ It may just be cheaper to buy one. For the cost of the acylic you get one chance. if you do it twice it would have cost the same. Most ppl have a hard time making overflow boxes that work. Unless your crafty.

Ironreef

It is more of a challenge than anything else.

U tubes can be found at most decent LFS. There are a couple in my area at least. Call around, you can probably find one.

-Perry

nope if the power goes out the siphon stops, kinda like a state of suspended animation. Atleast in my overflow?
The difference in mine though is that it is a h.o.b type of filter? But when the power goes out all water flow stops right there, then when power comes back on it all starts right where it left off

You can make siphon 'U' tubes pretty easy. Buy a 6' length of 1.25" OD x 1.125" ID acrylic tube for about $6. Cut off a 20" piece. Buy a 1.125" (1 1/8") diameter spring at Home Depot. Use a coathanger to pull the spring to the center of the 20" tube. Bend the coathanger in half for strength and then bend a small hook at the end. You will have to rotate the spring while pulling. Heat the tube using a heat gun or gas burner. A camp stove works fine. Keep moving the heat so you don't melt the tube. After a couple minutes you will be able to bend the tube into shape. Let it cool for a few minutes. Use the coathanger to pull the spring out. This is the trickiest part. You need to 'wind up' the spring as you pull. If the coathanger hook fails, it will most likely crack the acrylic as it pops off the spring. When the spring is out you can trim the 'U' tube to the correct length.

But, you can buy a U-tube at almost all lfs for about $5. Lee makes one in 1" and 3/4". Why go through all that trouble?

Regarding these siphon boxes, I'd be curious to know how you guys get the siphon started in the first place. Obviously the U-tube must be filled with water. My question is, how do you get the water-filled U-tube into the siphon boxes without spilling the water? My fingers are not wide enough, so once filled with water, I place small pieces of plastic/cling wrap over each end of the tube. I do all of this below the surface to ensure there are no air bubbles in the tube (what can I say--I'm anal retentive). Holding the wrap in place, I can maneuver the tube into the siphon box without spilling the water. Once the tube is in place I peel away the wrap and the siphon action starts! Does anyone have a better way?

From what I have read it is real simple. Put a piece of air line tubing up to the curve in the U tube. Then suck the air out. This will pull the water up the U tube and start the siphon. HTH

Mark

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And on the 40th day, God filled the ocean with sponges and saw that it was good.
-The unwritten verse in the Noah saga.

Mark,

Has the right idea on how to pull out the air out of the U tube.... Instead of sucking the air out with your mouth and getting a mouth full of salt water, what you should do is go ahead and place the one end of the line tubing in the venturi of a powerhead and let it do the work for you. Once the air is all out then pull out the tubbing. Serrota I like your idea on making the U tube but it sounds like a lot of work. I am going to call the LFS and see how much they will sell me one for.

Rico.