My P.O.P. is gone. need help again

[kelemvor]

What are your other chemical levels? If you've got no (or low) CYA that would explain the FC loss during the day. If you do, you may well be fighting algae.

[shub_31]

CYA 100
CA 110
PH 7.4
FF Target is 10ppm
FC .5 or less

[kelemvor]

Sounds to me like your fc is being eaten up by something rather than getting burned off by the sun with a 100CYA. I would shock to 25PPM. Keep shocking until you lose less than 1ppm FC between sundown and sunup.

You might also want to get some distilled water and mix that with pool water while doing your CYA test. Half pool water and half distilled, then double your reading to get your actual CYA number. I know my test kit only goes to 100PPM so if yours is the same, it's possible you have more than 100PPM CYA which would affect how much chlorine you need in the pool for normal use and/or shocking.

You should avoid using any dichlor or trichlor as those will increase your CYA level.

Edit: I see in your other posts that you recently tried a partial water replacement to reduce your cya level and it didn't budge. I think that probably means you were much higher than 100 and you'll have to do more water replacement than you already did to get it down some.

[shub_31]

Thanks for the reply. ive done pretty much all that from other members replies. They couldnt understand why my pool was doing what it was. its the clearest its ever been. I dont see how you can go ALL NIGHT WITHOUT LOSING FC. Ex. If you swim til 8pm. Add bleach up to 10ppm you should be guaranteed to lose ppm. The only way you would never loose was if nobody swam for days til you passed that test. I would think you introduce more contaminants every time someone swims. I shocked for 5 days but still lost 1-2ppm. So the experts recommended letting it drift down and see what happens.

[PoolDoc]

OK, some questions:
Are you saying you lose 4 ppm of FC between 8am and noon, with no one in the pool?
If there are people in the pool, who, and how many?
Do they use lotion heavily? Do they have leaky bladders? (Sorry, but it does matter!)

Changing direction:
Have you EVER used anything made by United Chemical: No Mor Problems, Yellow Treat, etc.?
Have you EVER used any other product sold in a 10" - 16" tall plastic jar, containing 1 - 2 pounds of white fine granular material that was supposed to help with algae, or in some other non-specific way, help your pool?

Ben

[shub_31]

Yes there are people swimming. 2 or 3. yes to lotion. no to the rest. I wasnt sure if its normal to start of at 10ppm then drop and not worry about it till evening. Im sure not everyone checks their pool all day and adds chemicals every couple of hours. thanks. I have added some clarifier about 3 weeks ago and some hth algacide weeks ago but quit

[shub_31]

oops. isnt it normal to lose ppm with 90 degree heat and sun even with noone in the pool