Thanks Ben - I don't have the exact mixture of shock in front of me but it's the shock I've always used. The one pound bag, purchased at Costco. I'll get the name in the morning. I thought about it and wanted to add this. Did you ever use the test kit where you add 5 drops of oto to water sample to get a chlorine level? If you had a lot of chlorine in the sample, the water would turn bright yellow, if you had a real lot it would turn bright yellow with one drop. This is what happened to the entire pool. The color is bright yellow/greenish so maybe saying its bright green is not totally accurate. Bright yellow/greenish would be more accurate. Instant chemical reaction.