Some folks just can't believe how quickly your pool can go through chlorine when you have algae, or that you can eliminate it with just chlorine. Due to major construction around my pool by a lousy construction crew (me ), I just got my pump and filter running yesterday evening. Big green mess. I don't have the main drain connected, so I can't vacuum. Here are my numbers and how things went. I'll update as it goes.
4/30 5:30pm-Dark Green, Can't see bottom step. CYA 35 [Update: This reading was wrong, apparently caused by the algae and debris in the water. It is actually below 20], pH 8+, No chlorine. Raised Cl to 15.5ppm with bleach. Blind brushed bottom and hopper walls. Added some muriatic acid.
4/30 8:30pm-Cloudy Dark Green, Can only see top step. Chlorine 4ppm, pH 7.8. Brushed some more and added bleach to go back to 15ppm. Added a little more HCl.
4/30 10:00pm-Cloudy Dark green. Chlorine 10ppm. Added bleach to get back to 15ppm. pH 7.6. Laid off the HCl to see where the pH stabilizes.
5/1 5:00am-Lighter Green. Can see all steps and can barely see dark places where I didn't brush in the shallow end. I can see the shallow/deep break line Filter pressure up 3psi, so I backwashed to maximize circulation. Chlorine 10ppm. Added bleach to bring it back up to 15ppm.
5/1 4:30pm-Hints of Blue in the water. Much clearer and I can see the bottom and all of the brush marks, but no main drain. Probably covered with crud since it's not on. Chlorine at 8.5ppm. pH at 7.2. Backwashed, then added chlorine to get back to 15ppm. Brushed the whole thing.
5/1 8:00pm-Cloudy again from the earlier brushing. Chlorine 12ppm. Pressure up 5psi so I backwashed again. More bleach and brushing.
5/1 10:00pm-Dark, so no clarity or color report. Chlorine at 14ppm. Pressure up 3psi, but I let it go.
5/2 5:45am-Noticably shifted toward blue-gray. If I could vac to waste, the water would probably be much clearer tonight. Chlorine at 8ppm. Backwashed and added chlorine to bring it back to 15ppm.
5/2 4:30pm-I have a main drain! Blue gray and clearer. I could see all of the places I'd missed brushing, so I churned them up. Chlorine was 7ppm after a heavy rain. Took it back to 15ppm.
5/2 10:00pm-Down to 9.5ppm. More bleach to 15ppm
5/3 6:00am-Very much blue-gray. Backwashed for 4 minutes to help get rid of rainwater. Chlorine at 9ppm. Raised it to 15.
5/3 9:00pm-Chlorine at 4ppm. Pressure up 5psi. Backwashed and added bleach. Brushed heavily.
5/4 7:00am-Water cloudy but no color to it. Backwashed and brushed. Chlorine at 12ppm. Added chlorine
5/4 10:00pm-Heavy rains all day. Chlorine at 6ppm. Added bleach and brushed.
As of ~96 hours into the process, I've used 29.5 gallons of 6% bleach.
The final few entries were lost in the forum switch. On May the 5th (I think) I reconnected the main drain which allowed me to start vacuuming. The improvement was pretty quick after that. I pronounced it absolutely clear on May 11th and returned the filter to timer control.