CYA and other chemicals after new plaster

[lvrpl]

I'm a new pool owner and am hoping to get some advice on adjusting the CYA level in our pool. We just had it replastered and it was filled about three days ago. The builder also added a bottle of Startup Tec (http://www.mcgrayel.com/startuptec.html) The builder has been helping with the startup but I'm taking over the chemistry starting today. I just tested my water this morning and this is what I've got:

FC = 1 ppm
CC = 1 ppm
TC = 2ppm
TA = 40
CH = 275 ppm
PH = >8.2

First of all, I clearly need to add some FC (I'm doing bleach) today and also some muriatic acid, right?

My other question is on the CYA level. My builder added two pounds of shock two days ago (this stuff from Leslie's, specifically - http://tinyurl.com/pv7odq3). In doing some reading here, it sounds like shock is not preferred for the TFP method and can raise CYA levels as a side effect. So here's my question - how much CYA should I add now (I've got some HTH brand stabilizer/conditioner)? Should I be worried that any CYA introduced via the two pounds of shock a couple of days ago isn't registering yet, and so if I add a full CYA amount based on the size of my pool I could end up with too much?

Thanks for any help!

 

[JoyfulNoise]

You need to get both TA and CH in that water. Please read this post about the bicarbonate startup process.

Yes, you need acid but not that much. If your CSI gets to negative it will adversely affect your beautiful new plaster. Your CSI needs to be between +0.3 to +0.7 for the first 2-3 weeks.


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[lvrpl]

Ok thanks for the quick response. I'll get some baking soda in there right now, along with a little acid and some bleach. I'll also put something in to raise the CH (that's the only thing I don't have on hand so I'll go get some this morning as soon as I add everything above).

I also forgot to mentioned that the builder used a bottle of Startup-Tec (http://www.mcgrayel.com/startuptec.html) - I'll edit my original post to include that there also. Thanks again for the help!

 

[JoyfulNoise]

Ok thanks for the quick response. I'll get some baking soda in there right now, along with a little acid and some bleach. I'll also put something in to raise the CH (that's the only thing I don't have on hand so I'll go get some this morning as soon as I add everything above).

I also forgot to mentioned that the builder used a bottle of Startup-Tec (http://www.mcgrayel.com/startuptec.html) - I'll edit my original post to include that there also. Thanks again for the help!

That stuff is just a sequestrant. What's your fill water, city or well? Do you have any known metal problems? What's the CH of your fill water?

You may not be able to find calcium chloride this late in the season. If you need to raise CH, you can use cal-hypo for chlorination. You get 6ppm CH for every 10ppm FC added by cal-hypo.


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[lvrpl]

That stuff is just a sequestrant. What's your fill water, city or well? Do you have any known metal problems? What's the CH of your fill water?

You may not be able to find calcium chloride this late in the season. If you need to raise CH, you can use cal-hypo for chlorination. You get 6ppm CH for every 10ppm FC added by cal-hypo.


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Fill is from city water. I have no idea if there are any known metal problems (we just bought the house last week) - is this something I would ask the city about? Or maybe a neighbor or something?

I'll test the CH of the fill water and post back in a minute.

 

[JoyfulNoise]

Fill is from city water. I have no idea if there are any known metal problems (we just bout the house last week) - is this something I would ask the city about? Or maybe a neighbor or something?

I'll test the CH of the fill water and post back in a minute.

City water is typically low on metals. Your fill water CH can be found out by calling the city water department or looking up water quality reports online. Measuring it yourself is better though. Check pH, TA and CH. Don't worry about chlorine or CYA.


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[lvrpl]

Ok, here are the results from the fill water:

PH - 8.0 (or maybe 8.2, I had a hard time with the color match for some reason)
TA - 60
CH - 100 ppm

Thoughts? I'm also going to go add some acid and baking soda (already did the bleach). Thanks again for the help.

 

[JoyfulNoise]

Ok, here are the results from the fill water:

PH - 8.0 (or maybe 8.2, I had a hard time with the color match for some reason)
TA - 60
CH - 100 ppm

Thoughts? I'm also going to go add some acid and baking soda (already did the bleach). Thanks again for the help.

Sorry, just another quick question - did you get that fill water sample from an outdoor spigot as opposed to an indoor tap? Since you mentioned just moving into the home, does the home have a water softener? I just want to make sure the water sample is representative of what the pool will be filled with. Outdoor spigots and pool autofill lines are typically on separate supply loops than the interior faucets.

 

[JoyfulNoise]

oh, and can you also test your pool water CYA? Don't worry about what the builder added. If he added shock, it probably wasn't all that much. But we do need to know the CYA number.

- - - Updated - - -

The stuff your PB added was calcium hypochlorite shock. So unless he added conditioner/stabilizer separately, then there's probably no CYA in your pool water. But please confirm with testing.

 

[lvrpl]

Sorry, just another quick question - did you get that fill water sample from an outdoor spigot as opposed to an indoor tap? Since you mentioned just moving into the home, does the home have a water softener? I just want to make sure the water sample is representative of what the pool will be filled with. Outdoor spigots and pool autofill lines are typically on separate supply loops than the interior faucets.

oh, and can you also test your pool water CYA? Don't worry about what the builder added. If he added shock, it probably wasn't all that much. But we do need to know the CYA number.

- - - Updated - - -

The stuff your PB added was calcium hypochlorite shock. So unless he added conditioner/stabilizer separately, then there's probably no CYA in your pool water. But please confirm with testing.

I did the fill water test with water from the outdoor spigot that was attached to one of the hoses we used to fill the pool, and the home does not have a water softener.

I tested for CYA and it came up with 0, I believe...I used the TF-100 kit (which has a tube with a black dot at the bottom you look at while filling with the test sample) and was able to fill the entire test tube and still see the black dot (sorry if you're not familiar with the TF-100 CYA test - the point is that, assuming I did the CYA test correctly, none showed up on the test).

So I guess I should go put some CYA in ASAP? I guess my only question was, if my builder had put any CYA in via the powder shock product, would it even show up yet given that CYA can take a week to fully show up on a test. But it sounds like there wasn't any CYA in the powder shock so there likely is no CYA in my pool, which makes sense given the test result I got of zero CYA. Do I have that all right?

Thanks again for the help, much appreciated.

 

[JoyfulNoise]

I did the fill water test with water from the outdoor spigot that was attached to one of the hoses we used to fill the pool, and the home does not have a water softener.

I tested for CYA and it came up with 0, I believe...I used the TF-100 kit (which has a tube with a black dot at the bottom you look at while filling with the test sample) and was able to fill the entire test tube and still see the black dot (sorry if you're not familiar with the TF-100 CYA test - the point is that, assuming I did the CYA test correctly, none showed up on the test).

So I guess I should go put some CYA in ASAP? I guess my only question was, if my builder had put any CYA in via the powder shock product, would it even show up yet given that CYA can take a week to fully show up on a test. But it sounds like there wasn't any CYA in the powder shock so there likely is no CYA in my pool, which makes sense given the test result I got of zero CYA. Do I have that all right?

Thanks again for the help, much appreciated.

Yes, it does seem you have no stabilizer in your pool. If I'm reading your signature right, you are doing manual chlorination with bleach, correct? If that is the case you need to get 30-50ppm CYA in the water. Since you are in Texas, I think a lot of TX folks use 50ppm due to the intense sun but you could always aim for 40ppm and bump it up later. You also need to get bleach in your water too up to your target FC and maintain it. Just add the CYA via the sock method and assume that your CYA is what PoolMath says it is. Then add enough bleach to reach your target FC level and maintain it there.

It seems like your water is pretty good quality (low TA, low CH and high pH). So your CH rise from evaporation should be fairly slow over the long run. Given your 60ppm TA fill water, you may find that your TA, in the long run as well, is quite stable and requires little, if any, baking soda additions. I would just try to follow the bicarb startup procedure as closely as you can. From my review of the process, it looks like you have plenty of CH for now and your main goal will be getting your TA up and maintaining pH on the high side (7.8-8.0). There are several good threads on people who successfully used the bicarb startup procedure so I would try to mimic what they did.

 

[lvrpl]

It seems that I'm having some trouble with my FC levels. Yesterday (Saturday) morning, I tested at 1 ppm for the FC as my first post says. So yesterday morning I added enough bleach to raise the FC level to 4 ppm per poolcalculator's instructions (I added about 38 oz of 8.25% bleach).

Then that night (last night) I tested the FC and again got about 1 ppm (maybe even a little less. So again, I added enough bleach to bring it up to 4 ppm. Then first thing this morning, I tested again and again got about 1 ppm.

Any idea what's going on? I added the CYA last night also, so maybe I lost all of my FC to the bright sun yesterday - would that be possible to lose it all in one day? And that still wouldn't explain the second overnight loss last night.

Any help is greatly appreciated!

 

[JoyfulNoise]

What form of CYA did you add, granular or liquid?

Given that you had 0ppm CYA, it is totally conceivable that all of your FC would burn off from the UV. You're going to have to test and dose regularly to keep your FC up.

How long did your fill water go without FC in it?


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[lvrpl]

I added granule CYA (the stuff from Walmart, applied with a sock).

Fill water went maybe 10 hours before the builder put in 2 pounds of that shock product from Leslie's that I linked in a post above. I turned off the hose at about 10:30pm on Wednesday when the original fill was complete and the builder came and put the shock in on Thursday morning around 8:30am. The next time FC was added was when I put that first batch of bleach in on Saturday. However, I think the pool water was slightly murky/greenish on Friday morning when the pool builder came back to brush, but it seemed to clear right up with whatever he did that day and he didn't seem too concerned. Am I in trouble?

 

[JoyfulNoise]

There is a chance you may have developed algae or your CYA is still too low. You should keep your FC at the high end and see what your FC consumption is. If you have trouble holding FC, then we may have to SLAM but I'd hope to avoid that while you're starting up your plaster.


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[JoyfulNoise]

Can you please post a full set of test results including TA and CH.


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[lvrpl]

Yes absolutely, will do as soon as I get back home in a few hours.

 

[lvrpl]

Ok just got these results:

Date: 7/26
Time: 8:00pm
Water temp: ~85 deg
FC = 0.5
CC = 0.5
CH = 325 ppm
TA = 80
PH = >8.2

I didn't test CYA because I just added it via sock last night so, as I understand it, it won't register for a few more days.

So what do you think? Go add enough bleach to raise the FC to 5 and retest after 30 minutes to verify? And add some muriatic acid?

Thanks again for the help, I'd really be totally lost without it.

 

[JoyfulNoise]

Ok just got these results:

Date: 7/26
Time: 8:00pm
Water temp: ~85 deg
FC = 0.5
CC = 0.5
CH = 325 ppm
TA = 80
PH = >8.2

I didn't test CYA because I just added it via sock last night so, as I understand it, it won't register for a few more days.

So what do you think? Go add enough bleach to raise the FC to 5 and retest after 30 minutes to verify? And add some muriatic acid?

Thanks again for the help, I'd really be totally lost without it.

If you are trying to do the bicarbonate startup then the critical parameter is this -

CH + TA = 500ppm

So based on this numbers, you need to get your TA up to 175ppm since your CH is already high enough at 325ppm. I would add acid to get your pH down to 7.6 and test to make sure you are there. Then add enough baking soda to get to 175ppm but break it up into two or three batches and test in between additions. You then need to hold the pH and TA for two to three weeks not letting the pH rise above 8 and adjusting down to 7.6 as-needed. The TA and CH should be checked regularly to make sure they are holding. Adjust those as needed.

Your FC definitely needs to get fixed. You've gotta keep it up to at least 5ppm. The CYA should be helping with the sun so you may need to baby sit this pool a little to see how well it is holding FC.


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[lvrpl]

Ok thanks. How long after I add acid can I test to see what the PH has adjusted to? I've read on other threads that, for bleach, I can add and then test 30 minutes later. Would acid be the same?

I also have another stupid first-time-pool-owner question. I'm starting to get some fine dirt or sand accumulating on the bottom of the pool but was told not use the Polaris 280 for 30 days after the replaster (and yes, I'm brushing twice a day still at this point and trying to direct these things to the main drains, but a good portion of it is just sitting on the bottom of the pool). Do I just need to buy a vacuum hose that attaches to the skimmer? Or something else?

Thanks again for the help.