What is the rust spot in my pool?
Most likely you have a rebar stain. Sometimes you will get rebar under the plaster that will rust out and the rust spot will come through. This happens because when the shotcrete was shot, the was a rebar that was not deep enough in the concrete, and thus the rebar not protected enough and the chemicals get to it and rust it out. The best way to fix rebar spots is to drain pool, cut out rebar and then patch area.
