I've been tempted to give this a try since I learned to do DIY zinc plating a few years ago. The difficult part would be in depositing a uniform layer of zinc along the multifaceted interior of the tank.
I think I've solved that with the idea of using an array of zinc anodes (made of zinc roofing strip (sheet metal roll) commonly available at home improvement stores) housed inside of several, maybe a dozen or two Perforated Practice Golf Balls, little whiffle balls.
A short length of zinc strip attached to an insulated wire, perhaps with a styrofoam peanut or two in some of them for buoyancy, held closed with a small zip tie. It would be easy to daisy-chain these and feed them inside through the filler cap, down both sides of the interior of the tank, agitation could be performed with the help of an electric timing motor and linkage to induce 'ocean waves' into a hinged plank the tank will sit on.
Thoughts?
