So... seasonal pool, 4th season. I know I have iron in the water and last season got a protocol for treatment more or less worked out. I finished filling the pool Thursday, bumped he pH up to 7.6, added the metal treatment and let that work overnight. I added 2 pucks to the skimmer and shocked the pool Friday morning. The water was still clear Friday night. FC was above 5, pH was 7.2, TA was 80. I added baking soda to bump the TA up a bit. Also, my wife wanted a bit more water in the pool so I added more. Saturday morning TA was 100, pool was clear, ph was 7.2. We used the pool in the afternoon. Last night it we got thunderstorms so I shocked the pool this morning and cleaned the leaves out. pH had fallen to 7, FC was still above 5, water was clear. I added soda ash to boost the pH. We went swimming this afternoon. ph was 7.2, FC was above 5, CYA was 30. I was feeling pretty good since I hadn't had the water issues I've had the last few seasons. Soon after we got out, the water started changing color. It is now brownish, but it is clear. What the heck is going on? I assume it is the chlorine reacting with iron or copper, but why all of a sudden? Do I just need more sequestrant? I thought once the initial treatment was done I only needed a few ounces a week. I don't want to just dump the stuff in when it is 20 bucks a bottle.