700 gal spa overflows into the 15,000 gal pool and I run in overflow for 4 hours each morning with the chlorine generator (pool pilot) at 100%. At the end of the 4 hours the chlorine is at 2 PPM. By the next morning, the chlorine is down to about 1ppm. pH is between 7.5 and 7.8.

With no one using the spa, each day there is a brown ring in the spa at the water line. It washes off easily, but I'm concerned that something is wrong. Can anyone tell me what's going on?

Thanks,

al