Pond Boss Forums INTRO Questions & Observations siphon question

I have a 6 ich pvc stand pipe or through pipe running through my dam which regulates pool and drains during storms. I am going to siphon my pond and stock it fresh with a different approach due to overstocking by previous owner. My question... Can I attach a rubber pipe clamp reducer (6" to 3") use some elbows and run 3" pvc out into the pond and get a siphon going? I am concerned that after capping and filling the 6" through pipe when I remove the cap that a siphon won't hold up due to the difference in pipe sizes. Will there be too much air in the system?

You Wildcats like to over think things! JUST KIDDING!

Just take two lengths of 4" sewer and drain PVC, use two elbows, two test plugs, turn it upside down in the water to fill it, put one side in the overflow, pull the test plugs (POND SIDE FIRST!!!!!)and watch 'er go.

Cut the length for the pond side about 3" longer than you want it drained and the part you put in the overflow about 2-3' longer. Essentially you'll be making an oversized U-Tube siphon.

Total cost should be under $25.

After re-reading your post, I see you want to totally drain the pond. You could still use the method I just said, but use your rubber collar adaptor and slide the tube going into the overflow through it so it will be below your water level. Cap the outlet of your overflow and use the U-Tube to fill your overflow. Once it is full, you can add length to your pipe on the pond side to get it on the bottom. As long as the pipes are all sealed, even a moderate amount of air being in the pipes at the start won't effect the siphon once it starts.

How deep is the pond? A siphon can only work at a max of twenty feet. Also put some sort of support under the short piece of PVC where it goes over your stand pipe, and/or use schedule 40, because once the level drops considerably, that pipe is going to get damned heavy and may even snap S & D pipe.

Rainman, thanks for the advice. I got her going today but after about ten minutes she quit on me. This happened twice. I believe air is making its way in at the outlet as only about half of the six inc pvc is streaming with water while flowing. I have seen where you can put an elbow on at the outlet pointing up to create an "air trap". I think I'll give that a shot and see if I can keep her going. Any thoughts? The pond is 12 -14 feet deep.

mbj
do you have a picture(s)? more likely air is coming from pond side but elbow on outlet wont hurt, just keep outlet below where you want to drop the pond to.

rainman, whats a test plug?

mbj, you're probably right. You may want to put electrical tape around any and all exposed joints as well, just to make sure they are all air-tight.

Cliff, a "test plug" has soft rubber sandwiched between two hard discs and can be expanded to seal the end of a pipe by tightening the bolt holding the hard discs together so you can "test" for leaks. You then loosen the bolt, and the plug is easily removed.

I have siphoned my pond by submersing a length of sandblasting hose underwater, capping one end, then shoving it down the overflow pipe and uncapping it underwater.