Syphon for water transport?

Don't confuse a thermo syphon circulation with a gravity syphon.
With the thermal version the inlet and outlet can be at the same height.
It is having the hot side in one vertical 'leg' which is important, the hot column of liquid is lighter than the cold one and that's what gives the imbalance and flow.
From a practical view point, to get a thermo syphon working you need big bore pipe, a good temperature differential and short pipe runs.

My guess is that you will need a pump, a mains central heating pump will do the job, and they are cheap.
Safety warning... Run it via an appropriate earth leackage trip, earth the body of the pump too, I assume you will be using plastic pipe but it is still essential to be safe.

You can easilly wire it via a temperature switch of some sort.
Del

Thanks for the reply Del. (Del the cat?)

I am looking now at a solar powered pump.

Any thoughts on what kind of power I would need to push this water up about a metre high, through 8 metres of 1" rubber hose?

Thanks again for your help.

Aquamom

Aquamom What size is the pool? Does it have a pump & filter? I had a 20.000 gallon pool and in early summer I attached a hose to the return line from the filter and diverted some water through a lawn sprinkler up into the air (90 + degree) and into the pool. This would more rapidly raise the temperature that started at 68 degrees. Late summer I would do the same thing but at night when the pool was 88 degrees and the air was around 70 degrees. This would more rapidly remove heat from the pool to make it more enjoyable. My preference was around 75 degrees. Good luck and enjoy with the youngsters. Jerrell

Not all that much power needed as any 'up'ness (technical term) will be counterballanced by the 'downosity' on t'other side. You are only really pumping against the friction.
If you have big bore pipe it's easier.
My solar hot water system uses 10mm copper pipe...the central heating type pupm couldn't pull the water through...but it pushed it through with no problem.
Have a look at by my blog (linked above) it may give you some ideas.
There have been some other good solar heating threads, one chap used pvc pipe, but he had a good head of water to force it through when you opened a tap.
Del

Del is correct to a point. Having done this, I would recommend using 3/4" black plastic pipe as feed and return lines. Once up on the roof, zig,zag a larger size pipe (3" black plastic schedule 40 would be optimal) with an air purge at the top and before the return leg to the bottom of your pool. The feed to the roof should start about mid depth of the pool. Use a torpedo level to make sure the roof pipes are ascending continuously, and street el's at the ends, where you have installed roof brackets or guy wires to keep everything in place. Plug both ends of your feed/return lines, then fill from the port for the air purge, trapping as little air as possible into the collector pipes. Remove plugs. Try this before you buy a pump (easy retrofit) and if you do need one, remember it doesn't need to lift the water, only circulate it. Marine catalogues have a bunch of stuff for 12vdc. if you decide to go with PV supply next year. A small galley pump will work for you.

Don't forget to drain it in the winter.