I took for aeration of water from the well-there is too much iron in the water, it is necessary to oxidize. After the first two hours heated and turned off. Cooling an hour, turned on again. Next, it has been working for 6 hours. Very hot. At a depth of 1 meter works well, but it is heard by sound, which is difficult. Complete tubes of food-grade silicone, which is very pleasant. It came in two weeks at Peter.