IntelliChlor IC40 Issues

[Watermom]

I also think if it were my pool, I'd try shocking the pool. Your cl is really low and you could have something starting to brew in the water which could be consuming the chlorine. See if you lose more than 1ppm of chlorine overnight after shocking.

[dchango]

Thanks for the info, I shocked the pool today with the powder shock, but I see it is mentioned using bleach for shock. Is liquid bleach better then the powdered stuff, should I shock it a couple times in a row? I also noticed a small spot (6 inch) of what appeared to be a greenish algae in the shade by the waterfall. I used the pool brush and it came right off. Other then that the pool is crystal clean or it at least it appears that way.

Thanks
Damon

[Watermom]

Depends on what the ingredient is in the powdered shock. (I just noticed that you have a plaster pool and didn't list a calcium hardness reading in your post above.) If the shock powder is dichlor, then no, I wouldn't use it. It has stabilizer in it and your CYA level is already high enough. If it is cal-hypo, you might be able to use it but can't comment on that unless we know your CH reading.

You should shock until you can go from sundown one evening until within 2 hours of sunrise the next day without losing more than 1ppm of cl, and have no greater than 0.5CC. While you are shocking, test a couple times per day and each time take the cl back up to 25pm. (See the Best Guess Chlorine Chart in my signature below for the connection between CYA and chlorine levels.)