I first heard about zapping aptasia from Reefbuilders forum and a pioneer in the field of building "zappers", Paul Baldassano. Here's the link to his original post on RC http://reefcentral.com/forums/showthread.php?t=1808040 You may wish to take the time to read the whole thing. It's very interesting and discusses early versions that experimented with a variety of power sources. DO exercise EXTREME care and caution when marrying electrical devices to your tank!!!!!!!!!!!! There's a LOT to consider! Here's what I gather: DIY zappers are pretty easy to build. Paul's final designs use a 24 volt DC "wall wart" power supply, a 24 volt light bulb to provide some resistance, a momentary switch to turn it on, a stainless steel needle attached to the negative lead (very important about polarity) for the "business end" potted in the end of a poly tube with the second contact being a carbon or graphite rod (carpenter's pencil lead) attached to the second conductor via a stainless steel spring. The second conductor (positive) may be as close as 1" from the stainless needle. The needle is covered with heat shrink tubing with about 1/4" exposed on the end. When activated and submerged in salt water, hydrogen bubbles form on the exposed needle tip (negative) and oxygen bubble form on the carbon conductor(positive). Yes, it's simple electrolysis, middle school science stuff. Neither gas seem to cause an issue with the fish or the coral in the tank BUT the aptasia react to the hydrogen gas and become gum balls after a short period of contact. The electricity itself is not a factor in the elimination. Summary: I think I'll build one and see how it goes. Lot's of units being built/tested now and talk of copy cat and inferior units being produced as well. Hmmmm. Anyone else walking down this path?