Just wanted to thank everyone that helped me. For the last 2 nights the chlorine has stayed at about 20ppm. The ph is 7.2. It is still not totally clear, but I can see all the steps of the ladder, so I think the algae must be gone. I have been out about 3 times already today brushing the bottom and sides and I think it is working. I think my small cartridge filter might just take awhile to totally clear it up. Again thanks to everyone.

Peggy