:bounce:The light weight float valves as shown are intended for use with low voltge systems (12 volt) not house hold line voltage. There is a plastic dip that is sold at hardware stores to coat tool handles, it would work much better than a plastic bag to cover the wire splices. I would also use crimp connecors not wire nuts. Most quality ATO systems use a 12 volt peristallic pump instead of a circulation pump. First it is more exact. Second its pumping capacity is small so even if the float is sunk by a hernit crab or a couple snails only a few gallons of water will be pumped in a day not your full container of top off water. Third a low volatage system is much safer to use in a water environment. A peristalic pump by itself wiould probably cost at least a hundred dollars. Mel's system will work, but it is something that requires particular things as noted in his writeup. Plus it is a system that would warrant a vigilant watch on its performance. It would be cheap though. I. myself, would not risk a tank full of corals on a cheap system such as this though. I would not risk even a few corals on Mel's DIY ATO set up. :^: