Test results on new pool in Tucson

OK: If you don't have algae and your CC level is .5 or less, then you need to keep your FC (free Chlorine) level in maintenance mode, not shock mode. With a CYA of 100 or more, Maintenance Mode means an FC of 8-15ppm. Shock mode means an FC of 25. So if your are between 8 and 15 and your level pretty much holds overnight, with only a small loss, you're golden.

I hope that helps.

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Originally Posted by Wilco

Ok , here's the last 24 hrs. Not encouraging. Yesterday 7 am, cl at 4, I added a gallon of bleach. Retested at 4 pm, it's at 5 ppm, with 1ppm cc, added a gallon retested at 5 pm it's at 10 ppm, added another gallon, an hr later at 7 pm it's at 16 ppm. Ran pump all night. Test this am showed 6 ppm, zero cc.

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Carl, in Wilco's overnight test he lost 10ppm FC. That's why WaterMom took him to shock level.

Wilco, we originally said 15 because with your CYA level, 8-15 is your maintenance range. Now that you have determined that you are losing FC overnight, we know you are fighting something unusual in your pool and need to shock it at 25.

Yes, you need to add bleach in the morning too. Your goal is to get it to 25 and keep it there as much as possible. If you can, make additions mid-day too.

Carl may have not read the entire thread. Shock level is what you want. Even though there is no algae, you have huge chlorine demand. So, you do want to shock the pool and keep it at shock level until you get past it. Sorry for the seemingly conflicting advice.

ok. guess ill be making triweekly costco runs. also, you all mentioned running the pump 24/7. what is the reasoning there?

Actually, without algae, probably not as critical. Usually when shocking a pool, it is to clear up an algae bloom and thus we say filter 24/7. In your case, probably not as necessary.

better to run at night or day? would it have any potential to prevent nighttime drifting of cl?

Doesn't really matter and it shouldn't have anything to do with the night-time chlorine loss.

Ok. Just hit 3gallons, should be at shock level---8+6+6+6 (will test)
Thank you all

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Originally Posted by Watermom

Carl may have not read the entire thread. Shock level is what you want. Even though there is no algae, you have huge chlorine demand. So, you do want to shock the pool and keep it at shock level until you get past it. Sorry for the seemingly conflicting advice.

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That would be true....oops. But if you're losing 10ppm overnight, it may well be some other contamination you have to metabolize. Algae is, in an of itself, harmless. But it "bleeds" the chlorine out of your water so it can't metabolize the really bad stuff, like animal, avian and human fecal matter, and other bacterial contamination. Algae's just the most obvious and visible.

I know, I don't get why the drop overnight. No visible issues with contaminants. Bather load is light. Pump is running relatively low pressure, but I guess I can do aa backwash. I still think it's somehow related to the extreme hardness of the water here. I have scaling all around the pool. Takes a toll on dishwashers, water heaters, shower doors in a major way here.