How often to test & how much chlorine to add daily? Also, vacation upcoming...

[CarlD]

It sounds like you either are still fighting something or miscalculated. I can't figure powder amounts--but bleach and LC I can do in my head...

Had you measured the pool an hour after you added the chlorine, you would know what the FC was then and there. If it was 4.5, then by this morning, you lost nothing.

Meanwhile, I don't know where you are but this season, for unexplained reasons, EVERYONE around the country seems to be using excessive amounts of chlorine--myself included. I've had to add a gallon of 12.5% the last two days.

[blessedbeingmom]

It sounds like you either are still fighting something or miscalculated. I can't figure powder amounts--but bleach and LC I can do in my head...

Had you measured the pool an hour after you added the chlorine, you would know what the FC was then and there. If it was 4.5, then by this morning, you lost nothing.

Meanwhile, I don't know where you are but this season, for unexplained reasons, EVERYONE around the country seems to be using excessive amounts of chlorine--myself included. I've had to add a gallon of 12.5% the last two days.

It wasn't powder that we added, it's just that DH uses the scale to measure how much to add, on the presumption that for 6% bleach, since most of it is water, it's of a similar density to bleach, and therefore 1000 grams is about 1000 milliliters (one liter).

We would have measured it last night again, but weren't sure how long it would take for the chlorine to be dispersed. We plan to check the level mid-day today since it is going to be a hot & sunny day here, and then again this evening. We plan to shock the pool Tuesday night, and then again before we leave for vacation.

We are in South MS, about an hour northeast of New Orleans.

[CarlD]

Why use a scale? I think you are doing it the hard way.

The rule of thumb for bleach is: 1 gallon of 6% adds exactly 6ppm to 10,000 gallons of water.

Since you have 5,000 gallons, you would need only 2 quarts of 6% to get a rise of 6%. 3/4 of that (a quart and a pint) would raise your FC by 4.5ppm.

Did you add 3 pints of 6% bleach?

BTW, if the bleach is 5.25%, substitute 5.25 for 6. If it's liquid chlorine and it's 12.5%, substitute 12.5 for 6.

You don't even need a calculator!

this is based on the formula for bleach addition:
FC added = (1,000,000/pool gallons) * 0.06 * # gallons of bleach, where 0.06 is 6% bleach. Use .125 for 12.5% LC.

[blessedbeingmom]

Why use a scale? I think you are doing it the hard way.

That's DH for you! He specializes in doing things the hard way. LOL! He's very scientific about everything! To be fair, he says the bottle is an odd size, so it makes it hard to measure it. I think we'll find an old pitcher or something and make quart and/or pint markings on it and use it for adding bleach, so we can do it the easy way, but for now, he's still doing it the technical way.
Okay, I was at work today & DH did not test the FC levels this afternoon. They were 4.5 ppm this morning. We swam at around 11:30. At 9 p.m. this evening, the FC was only 0.5 ppm. DH figured the amount of bleach to add to get it back up to 10 ppm and added 2,280 gm (about 2.28 Liters) of bleach. He checked the FC levels again at 11:45 (to allow time for circulation, and our level did not get up to 10 ppm. It only got up to 8.5 ppm.

Stay tuned for tomorrow's edition of "As the Pool (prayerful does not) Turn (into Algae) Again." LOL!

[CarlD]

OK,

That's very revealing. Thank you.

You are clearly fighting something in the water. That's why it's dropping so much. Of course, as I said, EVERYONE around the nation is using large amounts of chlorine this season. You need to add sufficient bleach to bring your FC up to shock level: 15ppm, and keep it there for at least 24 hours or until it stops dropping drastically. It may be as little as 24 hours. After raising the FC, check the water 3x a day and raise it back to 15 as needed. When, after 24 hours, it doesn't drop, or doesn't drop much (especially overnight, when there's no UV to break chlorine down, you can gradually let the FC drop back to the maintenance level which is 3 to 6 ppm and which is where you'll keep it on your normal daily basis.

[blessedbeingmom]

You are clearly fighting something in the water. That's why it's dropping so much. Of course, as I said, EVERYONE around the nation is using large amounts of chlorine this season. You need to add sufficient bleach to bring your FC up to shock level: 15ppm, and keep it there for at least 24 hours or until it stops dropping drastically. It may be as little as 24 hours. After raising the FC, check the water 3x a day and raise it back to 15 as needed. When, after 24 hours, it doesn't drop, or doesn't drop much (especially overnight, when there's no UV to break chlorine down, you can gradually let the FC drop back to the maintenance level which is 3 to 6 ppm and which is where you'll keep it on your normal daily basis.

Okay, so last night Matt added enough bleach to get up to 17 ppm. This was at 11:15 p.m. In the morning, by 7:15 a.m., our FC was only 12 ppm. He added enough bleach to get up to 20 ppm this time (as we were both going to be away from the house all day today). I came home and checked it at 6 p.m. and the FC was down to 5 ppm. Again, it was a very hot and sunny day (pool water temperature of about 93 degrees). The CC was only 0.5 ppm.

We will bring it back up to shock level again tonight before going to bed. I bought a pitcher that goes up to 2 quarts and wrote "pool" and "bleach" all over it (so we won't use it for anything else). On the side where the markings are, I wrote lines for 1.5 ppm, 3 ppm, 4.5 ppm and 6 ppm, to make adding bleach easier.

How many ppm is normal to lose at night, and how many is normal to lose on a hot, sunny day?

So, for our vacation, the plan is to raise to shock level before we leave, then cover (but vent). Set timer to run pump for 2-3 hours at a time, several times a day. Mid-week (after about 3-4 days) have relative come by and add a gallon of bleach (should raise it by 12 ppm) and keep pool covered but vented. Does this sound okay? Do we need to add any stabilizer? It was about 42 ppm six days ago.

[CarlD]

Your chlorine loss should be negligible, not massive. I think you have a fight on your hands (with something that is using up your chlorine.)

Remember: You want the chlorine there to kill dangerous contaminants. Not to be too disgusting but every person who gets in your pool brings a very,very, very small amount of fecal matter--and the chlorine rapidly neutralizes that and renders it safe, sanitary and harmless. If algae is using up your chlorine you lose that protection.

That should reassure you that doing this is the right thing.

[aylad]

Carl's right--you're fighting something in the water. Your chlorine loss overnight should be less than 1 ppm. It will be more during the day, but shouldn't be nearly as much as you're reporting. You need to shock it and hold it at shock level as consistently as you can to kill off whatever is creating your chlorine demand. As far as vacation, your plan sounds good--but if that bleach-adding relative could come by a couple of times, maybe on day 2 and day 4 or 5? it would be even better.

Janet

[Watermom]

That's DH for you! He specializes in doing things the hard way. LOL! He's very scientific about everything!

Um, yeah. I know somebody (who shall remain nameless) but his initials are P.o.c.o.n.o.s. who is just like that!

Stay tuned for tomorrow's edition of "As the Pool (prayerful does not) Turn (into Algae) Again." LOL

Love it! Gave me a good chuckle this morning!

[AnnaK]

Meanwhile, I don't know where you are but this season, for unexplained reasons, EVERYONE around the country seems to be using excessive amounts of chlorine--myself included. I've had to add a gallon of 12.5% the last two days.

Yep, count me in with that group.

I decided to raise my CYA from its normal 40 ppm to 60 ppm which has noticeably reduced the frequency and amount of chlorine additions. I'm running the FC at 5-7 ppm now.

It's been a weird season. Late to warm up, lots of rain in the spring, then a nasty heat wave with no rain at all which is making demands on my well for refills.