I use the nice plastic waterers in the warm months- but I need the galvanized ones for the heater in the winter. The first one I bought lasted a couple years, I saw that it was getting rusty. I bought a replacement. This one got rusty in a matter of months. If I keep it washed out, is there a problem with it being rusty?? Don't want to hurt my birds- but getting tired of spending money on these things that don't last....