Where to Start? Low CYA

[indyattic]

I have an above-ground, about 13,000 gallons. I bought a boatload of chemicals this morning: bleach, muriatic acid, stabilizer, baking soda, borax - I'm ready to start.

This pool sat uncovered and empty for at least a year, maybe 2. We've been scooping and cleaning for 2 weeks. We're finally able to see the bottom and we want to start the algae battle. I ran the numbers through the calculator to get a feel for what we need to add.

Reading the instructions, it seems that our CYA level needs to come up before we shock. But I also get the impression that it takes a loooong time to dissolve in the water. So, do we add the sock 'o stuff and just shock based on the current readings, or do I have to wait a few days for the stabilizer to take hold?

Our water chemistry results are below. (From TPS: bought a test kit while I was there.)

FC: 0.0
TC: 0.1
CC: 0.1
pH: 8.2
Hardness: 150
Alkilinity (W/ stabilizer correction): 237
CYA: 10
Copper: .5
Iron: 0.0

 

[TizMe]

There is a section in Pool School about balancing your pool water and chlorinating your pool you might want to read up on.

Your TA is extremely high and needs to be taken care of as soon as you get your CYA set and your chlorine done. Your TA should be between 90- 110ppm.

With a CYA of 10 you can shock to 10ppm.

 

[chem geek]

Reading the instructions, it seems that our CYA level needs to come up before we shock. But I also get the impression that it takes a loooong time to dissolve in the water. So, do we add the sock 'o stuff and just shock based on the current readings, or do I have to wait a few days for the stabilizer to take hold?

If you want to add both chlorine and increase CYA at the same time fairly rapidly, you can use Dichlor granules/powder. For every 10 ppm FC added by Dichlor, it will also increase CYA by 9 ppm and will dissolve rather quickly. This is one of the few times when using Dichlor makes some sense. In terms of cost, it's only a little more expensive than separately adding chlorine and pure CYA.

Richard

 

[frustratedpoolmom]

I would suggest, since you have the chems already....

Use the pool calculator to determine dosages - and first lower your PH to about 7.4. After an hour or two from when you add the Muratic Acid, go ahead and start shocking. Do not add liquid chlorine and Muratic Acid at the same time. Follow proper safety protocol when using the MA... After you add the bleach, go ahead and add the CYA, via the sock method. Restest the chlorine after sunset, adding more chlorine to bring it back to shock level. Your CYA won't fully register on tests for about a week, if you are using granular form. So don't worry about retesting that until Friday or so.

Keep adding chlorine to bring your pool to shock level; when you FC holds overnight or you lose less than 1ppm, you should see your pool clear up, your algae will be goners....! then you can let the FC drop into the recommended range for your CYA. About that time you'll be ready to retest the CYA and you should keep your FC at the recommended amount according to your CYA. Remember, try not to overshoot the CYA.

Your PH will continue to read high when your pool is at shock level; that's why I suggest you do that first.

When your pool is cleared up, you can see about lowering the TA. There's an article in pool school. But that's not as pressing right now. Good luck! Hope this helps. :-D

 

[indyattic]

Oh it all helps! I am going to add the muriatic acid now, and then hurry up and wait.

Rarely am I in the mood to actually do chores. How ironic that I can only wait for the chemicals to react.

 

[Butterfly]

Well, I am just gonna' ask about your .5 copper level.

Seems that I have read that anything over about .3 can cause you some problems (i.e. not be handled w/sequesterant) and need to be addressed,
but I will have to wait for those that know to chime in!

Have you tested your fill water?

I agree w/FPM that first, lower your pH! :-D

 

[indyattic]

Well, I added the acid, then dear hubby added the bleach after a couple of hours.

I just went to check my FC level, and found that my test kit only scales up to 3.0 - Argh! So I had to resort to the stupid, hard to interpret strips.

And it started raining.

 

[indyattic]

I have a question - can I vacuum the pool while getting my water properly adjusted, or will stirring it up give me inaccurate results?

 

[JasonLion]

Yes, you can vacuum. Stirring things up could throw the CYA reading off, but the rest of the tests will still read correctly. You want to get all of the debris you possibly can out of the pool before shocking. But you can go ahead and adjust the PH, TA, and CYA level right away.

 

[indyattic]

Thanks! We had vacuumed it quite well, but it's fall and the trees are dropping "stuff." I don't want to get behind.

An update ...because my test kit only goes up to a 3, i am using stupid test strips until I can get a better test. (I am going to order it off this site.) Last night we dropped 2.5 ppm in 2 hours. We added chlorine per the calculator to bring it back up to 10ish.

It rained a little overnight.

Got up this morning and it was down to 5.5. So we calc'd and chlorined again. Had to run errands, came back and it was 7.5 again. So we calc'd and added chlorine. Now we start scrubbing.

Anybody want to come over and help ?

 

[indyattic]

I have another question: Can I get into the water to scrub without doing my skin harm? My FC is (hopefully) around 10, and my CYA is at 10.

 

[indyattic]

Woot! I finally have held my shock for a whole hour!

 

[frustratedpoolmom]

Progress! LOL

As for swimming at shock level, not really recommended, but if you wore an old suit and showered after, I don't think it would hurt your skin. Of course if you sense burning sensation or anything get out and shower off.... I don't think it would hurt your skin but it might fade the suit, maybe?

 

[indyattic]

Progress! LOL

As for swimming at shock level, not really recommended, but if you wore an old suit and showered after, I don't think it would hurt your skin. Of course if you sense burning sensation or anything get out and shower off.... I don't think it would hurt your skin but it might fade the suit, maybe?

Heh! I ended up going in. I wasn't swimming yet, I was scrubbing. I think it made a difference. I have now held my 10 ppm for 2 entire hours! And my TA is down to 180 from 257.

It is so wonderful to see some progress. There was so much muck that it took us 2 weeks of scooping, filtering, scooping, filling...over and over and over - getting to the point of actually adding chemicals was a huge milestone.