So this is just a thought on my end, but have any of you heard of a product called Plasti Dip? If not just youtube it and you will see what I am talking about. In this situation it could prove very useful. If you are worried about the stainless steel leeching anything into the water if it makes contact with the water then why not coat the stainless frame with plasti dip? It's a sprayable, water proof, durable, and removable coating. People spray their cars with it, I've used it as a background for an aquarium, I used it to make the pvc for my plumbing in my tank black instead of white. It doesn't leech any chemicals once dry and it peels right off. Add enough coats and the steel would be waterproofed. Then there would be no corrosion at all. It's actually pretty cool stuff, and you could make it whatever color you wanted. Like I said I know it's not gonna be harmful to the fish, as it's inside my tank currently, and it just peels right off if you don't want it there anymore..I just figured I would share what I knew about a possible solution to the problem.