Update:
We had to go with the overflow idea, so I went looking for a container to make one and came accross a shower caddy (for bars of soap). It's made of clear acrylic/plastic, my husband is sealing off the bottom to make the drain hole. It already has suction cups, but I believe he is also going to make a hanger that I can silicone to the back of the tank. Pretty much a ready made overflow. I went to the hardware store and purchased a few feet of hosing. But now that I think about it, should I make the hosing coming from the fuse to the main tank (via overflow) a larger size verses what is going to be used from the main tank up to the fuge?