CYA and other chemicals after new plaster

[JoyfulNoise]

Good news.

Forgot to answer your question - no swimming during a plaster cure BUT it sounds like you won't need to SLAM at all.



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[lvrpl]

Ok, sorry for the lack of updates - I've been travelling for work (but had had someone helping out with the pool testing and chemicals). Things have been bouncing back and forth between looking really good and looking just ok. The FC losses overnight will be 0.5 or so for a couple of days, and then more like 1.5. FC losses during the day will be 2 or so for a few days, and then more like 5 for a few days. Makes me think that I'm not totally sure there isn't something growing in there so I guess the best course of action is to do a SLAM when we hit 30 days post-plaster, which is this Friday. Sound like the right approach?

On the plus side, the water is and has been crystal clear for the last few weeks. I'm also getting cotton from the trees like you wouldn't believe still (sometimes it falls in like it's snowing faster than I can pick it out with a net), so maybe that's eating up a bunch of the chlorine. Supposedly the trees only drop cotton like this for 3 or 4 weeks per year so hopefully we get to the end of it soon.

Also, I was brushing yesterday and noticed something I hadn't noticed before - there's some black stuff on the grout between some of the tiles that are under the spa spillway. I think I hadn't noticed it because the pump has been running continuously and so the view of that tile has been obstructed by water pouring over that spillway. Here are three pictures of the black stuff on the white grout - that's not algae, is it? It doesn't seem to really come off with brushing, but it's hard to get good leverage to brush it because I'm not down in the water. And it also seems weird that it would only be on the white grout and only under the waterfall, but what do I know?







For reference, here's zoomed out picture of the spillway:

 

[JoyfulNoise]

OK, here's what I think -

1. Finish up your plaster startup and then start bringing your pH and TA down to normal levels. You're going to need to follow the procedure for lowering TA that's in PoolSchool (Acid/Aeration process). You're new plaster can potentially keep raising your pH for at least the next year so just buy stock in a muriatic acid manufacturer and keep it on hand.

2. After plaster start-up is finished, you should raise your water to shock level and perform an OCLT (overnight chlorine loss test). This will tell you if your water has something funky growing in it.

3. As for the black stuff....well, that's weird. Try using a tooth brush and a cup of bleach to scrub it and see if it lightens the stain at all. If not, then try scrubbing it with a little vitamin C to see if that lightens the stain. Finally, if all else fails, use some diluted muriatic acid to etch the grout a little and see of that gets rid of it.

Dude, love the pool!!! Beautiful. I love new, white plaster, it always looks so clean!

One minor gripe, busy-body, Mister-Know-It-All, piece of unsolicited "advice" - Did you seal the flagstone on the spa spillway? I love FS and I have FS coping all around my pool but I would not have used it for a spillway surface. It's a soft stone and water penetrates it easily. Unsealed flagstone with water constantly flowing over it is very likely to erode over time. Don't get me wrong, I think it looks awesome but I think you need to consider sealing it to protect it.....your stone mason and others on the forum may be of a different opinion so consider all options.

 

[lvrpl]

Thanks for the compliment on the pool! We're really excited with how it turned out, now we just need to swim in it.

Good question about the flagstone - I have no idea if it was sealed. I have no idea. Didn't know that was a questions that should be asked (I didn't know anything about pools a month ago...things change quickly!) Thanks for pointing that out.

So if Friday is 30 days post-plaster, I can raise the FC to shock level this weekend and do an OCLT, correct?

Also, my pump should still be running non-stop, correct?

Thanks!

 

[kriv]

Looks great!!

 

[JoyfulNoise]

Thanks for the compliment on the pool! We're really excited with how it turned out, now we just need to swim in it.

Good question about the flagstone - I have no idea if it was sealed. I have no idea. Didn't know that was a questions that should be asked (I didn't know anything about pools a month ago...things change quickly!) Thanks for pointing that out.

So if Friday is 30 days post-plaster, I can raise the FC to shock level this weekend and do an OCLT, correct?

Also, my pump should still be running non-stop, correct?

Thanks!

Just ask the PB or the stone mason that did the work if they think you should seal it. I have unsealed flagstone all around my pool but none of it sees continuos water flow, just splash out. There's always a big debate here on threads about sealing versus not sealing when it comes to soft stone like flagstone or travertine. I personally like the color of my FS and I don't want to go through the hassle of sealing it all. So I'm willing to trade off a shorter life span for a more natural look and feel. To each his own. But, for a flowing water surface like what you have, I'm not so sure I would be so cavalier. Just ask, no harm in asking.

Yes, so when Friday rolls around, start bringing your pH down. It's probably going to bounce right back up again, but just keep bringing it down. As you're doing that, adjust your FC to shock level based on a current CYA reading. Use the FC/CYA ratio chart in pool school to determine your shock FC level and use Pool Math to get your dosing information. Then when the sun goes down, get it set to shock level and then remeasure the following morning. Make sure your pumps are running night long. If you lose 1ppm or less and your CC's are less than 0.5ppm, then you're all good.

Your last chore will be the best one - GO SWIMMING

- - - Updated - - -

If you want to run a full battery of tests and post the results before you start your OCLT, feel free. It would be helpful to know where your water started.

 

[lvrpl]

Just ask the PB or the stone mason that did the work if they think you should seal it. I have unsealed flagstone all around my pool but none of it sees continuos water flow, just splash out. There's always a big debate here on threads about sealing versus not sealing when it comes to soft stone like flagstone or travertine. I personally like the color of my FS and I don't want to go through the hassle of sealing it all. So I'm willing to trade off a shorter life span for a more natural look and feel. To each his own. But, for a flowing water surface like what you have, I'm not so sure I would be so cavalier. Just ask, no harm in asking.

Yes, so when Friday rolls around, start bringing your pH down. It's probably going to bounce right back up again, but just keep bringing it down. As you're doing that, adjust your FC to shock level based on a current CYA reading. Use the FC/CYA ratio chart in pool school to determine your shock FC level and use Pool Math to get your dosing information. Then when the sun goes down, get it set to shock level and then remeasure the following morning. Make sure your pumps are running night long. If you lose 1ppm or less and your CC's are less than 0.5ppm, then you're all good.

Your last chore will be the best one - GO SWIMMING

- - - Updated - - -

If you want to run a full battery of tests and post the results before you start your OCLT, feel free. It would be helpful to know where your water started.

Got it, makes sense on the sealer. I'll call the pool builder and ask him in the next day or two.

On Friday when I start to bring the PH down I'll shoot for the low end (7.2) because my PH has been spiking so frequently and quickly lately. I'll do the full battery of tests on Friday before I start also and post them. I also got the 50 ppm CYA control bottle so I can make sure I'm testing CYA correctly.

Also, I think I want to try and add borates to try get a little extra help on FC consumption during the day and to provide a little extra algae protection. Should I wait until the SLAM is done to start adding borates?

Thanks again for the help!

 

[JoyfulNoise]

Got it, makes sense on the sealer. I'll call the pool builder and ask him in the next day or two.

On Friday when I start to bring the PH down I'll shoot for the low end (7.2) because my PH has been spiking so frequently and quickly lately. I'll do the full battery of tests on Friday before I start also and post them. I also got the 50 ppm CYA control bottle so I can make sure I'm testing CYA correctly.

Also, I think I want to try and add borates to try get a little extra help on FC consumption during the day and to provide a little extra algae protection. Should I wait until the SLAM is done to start adding borates?

Thanks again for the help!

You should only bring the pH down that low if you are trying to lower the TA. I can tell you that for sure it will not stay that low for long. I'd be willing to bet your back up to 7.5 within a couple of hours. Once you get your TA lowered to where you want it, you should aim for a pH of 7.5 or so. There's really no good reason to try to keep your pH any lower than that now that are starting with fresh plaster and new water.

Hold off on the borates for now. You're going to be spending a lot of time trying to dial in your pH and TA and you don't need to add another chemical to the process. Anyway, borates are more for pH control than for helping with FC. Not everyone sees a benefit in FC consumption. Again, once you get your TA and pH stable, then you can do borates to really help keep the pH stable. But that's down the road. When you do go for borates, you should consider the boric acid method over the borax/MA route, it will be a lot easier.

Keep us posted.


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[Agent99]

Ah, yes, welcome to the wonderful world of new plaster (I'm on day 35 of a new Pebble Sheen refinish) and constantly rising pH! It is a joy...NOT! LOL

I'm thinking I should replace the liquid chlorine in my Liquidator with muriatic acid!! (just kidding...very bad idea)

After 4 weeks of new Pebble Sheen, I finally had knocked my TA down to 70 from the fill water 120 and added good old Arm & Hammer baking soda to bump it back to 100.

By virtue of keeping your pH in line with acid, you will slowly knock your TA down.

The speed at which the pH raises WILL SLOW DOWN over time. I'm already finding that I'm adding acid less and less frequently but it is still a couple times a week.

At least checking the pH is a piece of cake.

 

[lvrpl]

Ok, i just did the full set of tests so that I can start the SLAM this weekend. First of all, I was pretty shocked at some of these results...

FC 5.5
PH 7.6
CYA ~25 (I did it a few times, came out between 20 and 30 each time, but probably a little closer to 20)
TA 40
CH 450

Ok, so first up, the TA - what on earth happened here? This was at 120 a week and a half ago. Is this kind of a drop normal? We had some pretty torrential rain and I did a big backwash last week, but I wouldn't have guessed that would have been responsible for that big of a drop. Hopefully I didn't do too much damage to the plaster Do you think I killed myself here?

Next up, CYA - again, very strange. I added enough CYA according to poolmath a month ago to take me to 40. Then two weeks later, it was at 10 or 15, so I added enough to take me to 50....and now I'm measuring a bit over 20. Maybe I really did flush a ton of water with that backwash and rainstorm? At least this further explains why I'm losing 3 to 5 FC during these hot Texas days.

CH - wow, that was a huge rise. My fill water was 100. A few days after fill I measured 275, and about a week after fill it was at 325. Is that much of a rise normal? Anything to worry about?

So can I still go ahead with the SLAM starting today? I obviously need to add some baking soda to get the TA up and will do that right now. How should I deal with the CYA issue? I'll add more CYA to get up to 50 - should I SLAM to an FC level as if I have 50 CYA, or as if I have 20?

As always, thanks for the help! I'm still shocked at how that TA level got away from me.

 

[Agent99]

Sounds like the extra water (rain) and backwashing did do a number to your pool chemistry balance. Although I'd be thrilled to have to deal with rain problems--hahahaha!

Was there a reason to SLAM? I read back a bit and looked at your pics...water looks good. Is it clouding up or something?

I'll defer to others as to your CH skyrocketing issue.

I would add baking soda to get your TA back up to 100ish...easy enough.

I would also add more CYA to hit 50.

 

[pooldv]

I wouldn't go that high on TA, I would go to 60 and see how the PH acts. It would take about 180oz of muriatic acid to lower TA from 120 to 40. Is that in the ballpark? Have you had that much PH rise? Are you running any waterfalls, bubblers or other water features that are aerating and raising PH?

There is bacteria that consumes CYA and it is more active this year. If you need to SLAM only raise CYA to 30. Pool School - SLAM - Shock Level And Maintain

Did you add any CH? The only places that CH can come from is adding it, fill water or leaching from your plaster.

Why do you need to SLAM? What does the water look like?

 

[pooldv]

Isn't TA the test that needs to wipe the dropper between drops to release the static electricity? Did you do that the first test? If not then you could get a false high test.

 

[lvrpl]

I was planning to do a SLAM because over the last 30 days, about 1/2 or 1/3 of the nights have experienced a FC loss of greater than 1.0 ppm. There have been plenty of nights that have been less than that, but just to be safe, we figured we should do a short SLAM once I hit 30 days on the new plaster. Other than the second day after the fill when the water got a bit green, it's been pretty clear. I guess the SLAM is just to be safe given the number of nights where I've lost more FC.

I wouldn't go that high on TA, I would go to 60 and see how the PH acts. It would take about 180oz of muriatic acid to lower TA from 120 to 40. Is that in the ballpark? Have you had that much PH rise? Are you running any waterfalls, bubblers or other water features that are aerating and raising PH?

There is bacteria that consumes CYA and it is more active this year. If you need to SLAM only raise CYA to 30. Pool School - SLAM - Shock Level And Maintain

Did you add any CH? The only places that CH can come from is adding it, fill water or leaching from your plaster.

Yes, actually, I've probably added more like 220 fl oz of acid over the last couple of weeks. I guess I didn't realize that the acid would lower TA - rookie mistake on my part. That would explain the lower TA. I've added some backing soda and will retest soon.

Interesting on the CYA bacteria. I've added almost 4 lbs of stabilizer so I'm still surprised my CYA is at ~25, so maybe that had something to do with it in addition to the extra rain and backwashes.

I haven't added any CH at all. It would seem to make sense that it's coming from the plaster given that the plaster is only 30 days old.

I'm going to add a little CYA and than start the SLAM - hopefully it only takes me a day or two. Thanks guys!

 

[JoyfulNoise]

I was planning to do a SLAM because over the last 30 days, about 1/2 or 1/3 of the nights have experienced a FC loss of greater than 1.0 ppm. There have been plenty of nights that have been less than that, but just to be safe, we figured we should do a short SLAM once I hit 30 days on the new plaster. Other than the second day after the fill when the water got a bit green, it's been pretty clear. I guess the SLAM is just to be safe given the number of nights where I've lost more FC.



Yes, actually, I've probably added more like 220 fl oz of acid over the last couple of weeks. I guess I didn't realize that the acid would lower TA - rookie mistake on my part. That would explain the lower TA. I've added some backing soda and will retest soon.

Interesting on the CYA bacteria. I've added almost 4 lbs of stabilizer so I'm still surprised my CYA is at ~25, so maybe that had something to do with it in addition to the extra rain and backwashes.

I haven't added any CH at all. It would seem to make sense that it's coming from the plaster given that the plaster is only 30 days old.

I'm going to add a little CYA and than start the SLAM - hopefully it only takes me a day or two. Thanks guys!

@lvrpl

You have done a phenomenal job on the pool and it looks great. I feel I should have been more specific about telling you the affects of acid on TA but that's my fault - I often forget that people can't read my mind. You are on the right track and you should focus on getting your various chemical levels to the recommended ranges. I see no problem with a SLAM and you could even just try raising the FC to 10ppm and doing another OCLT. But you should definitely enjoy the pool now that you've completed all that hard work - especially keeping anxious kids out of the pool!!

As for the CH, I do believe it is normal to see a rise like that with curing plaster as there is plenty of calcium oxide and calcium hydroxide that can get converted to calcium carbonate and make it's way into your water. Just keep an eye on it and use PoolMath to check your CSI. If you can target a CSI of near 0, I believe your water will be just fine.

Congrats on your new pool!!

Sincerely,
Matt

 

[pooldv]

This link will help with chemicals and what they do.
Pool School - Recommended Pool Chemicals

 

[lvrpl]

@lvrpl

You have done a phenomenal job on the pool and it looks great. I feel I should have been more specific about telling you the affects of acid on TA but that's my fault - I often forget that people can't read my mind. You are on the right track and you should focus on getting your various chemical levels to the recommended ranges. I see no problem with a SLAM and you could even just try raising the FC to 10ppm and doing another OCLT. But you should definitely enjoy the pool now that you've completed all that hard work - especially keeping anxious kids out of the pool!!

As for the CH, I do believe it is normal to see a rise like that with curing plaster as there is plenty of calcium oxide and calcium hydroxide that can get converted to calcium carbonate and make it's way into your water. Just keep an eye on it and use PoolMath to check your CSI. If you can target a CSI of near 0, I believe your water will be just fine.

Congrats on your new pool!!

Sincerely,
Matt

Thanks! Oh and no worries about the acid affect on TA. I should have caught that in the reading. And I'll keep an eye on the CSI number. Thanks for all of the help along the way so far!

- - - Updated - - -

Isn't TA the test that needs to wipe the dropper between drops to release the static electricity? Did you do that the first test? If not then you could get a false high test.

Ya, that's right for the TA test, but I've wiped the dropper as the instructions say every time I've done that test. My guess is that I'll the acid I've been adding to keep the PH down while the new plaster cures was what drove the TA back down.

- - - Updated - - -

Ok, I did the OCLT test last night. FC loss was 0.5 and CC loss was 0.5 (and we had a LOT of crud get blown into the pool overnight from some wind gusts). Do I need to do one more OCLT tonight? Or am I good to go? Thanks!

 

[pooldv]

I think you are good to go. You can raise FC to 10 or so for a few days if you want to oxidize any extra organic matter that might be hanging around. Raise your TA to 50 and see how the PH acts. I would keep it between 50 and 60 and see how it goes. Keep your CSI between -0.5 and +0.5. And definitely keep your PH 7.8 or less. Looking good! You are almost a pool pro!