CYA and other chemicals after new plaster

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lvrpl said:
Alright, got home from work today and tested. PH is at 7.8. Is that good, or should I push it down to 7.5?

The FC tested at 3.0...even with having my wife add some bleach around mid-day. That means I probably burned up 6 or 7 ppm during the day today. I'll test the CYA levels tomorrow - hopefully that's getting absorbed into the water to help with the sunlight burn. I'll also do the FC overnight tonight again and see how much we lose - I'm skeptical that I'll get a repeat of a 1.0 drop like last night.
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Don't push the pH any lower than 7.6. Then measure your TA and adjust it up as necessary. Remember for the bicarb startup you want TA+CH = 500ppm. Then your plan will be to measure pH and TA regularly (probably daily for the first week) and keep the pH below 8.0 (maybe target 7.8) and the TA+CH at 500ppm. That will saturate your water with alkalinity and give you the plaster surface you want.

As for the FC, keep it at 5ppm as best you can and just keep an eye on your water. We really can't SLAM it right now but you can try to stay at your high limit. Just realize that you need to have your FC below 10ppm to accurately measure pH.
 
Tested this morning at 7:00am and interestingly got an FC of 7.5, which was down from 8.0 that I measured last night at about 10:00pm.

PH creeped back up to 8.2 last night when I teasted and so I put some acid in last night. It's back down to 7.8 this morning.

What do you make of the overnight FC losses being 1 or less for the last two nights? I'm still losing 4 to 6 ppm or so during the day though.
 
lvrpl said:
Tested this morning at 7:00am and interestingly got an FC of 7.5, which was down from 8.0 that I measured last night at about 10:00pm.

PH creeped back up to 8.2 last night when I teasted and so I put some acid in last night. It's back down to 7.8 this morning.

What do you make of the overnight FC losses being 1 or less for the last two nights? I'm still losing 4 to 6 ppm or so during the day though.
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An overnight loss of 0.5ppm is acceptable. During the day, you are fighting against the Sun and heat mainly. In a typical, clean pool, it is not uncommon to see FC losses of 2-3ppm during the daytime. You are in Dallas, TX, where it is blazing hot right now, correct? Well, if the pool is hit with sun all day and your CYA is on the low side, then between fighting organics, algae growth (algae is ALWAYS trying to grow) and UV, losing 4ppm is not out of the realm of possibility. This is why we need to nail down your CYA number too.

Get the pH down as best you can to 7.6 (it's going to want to rise quickly) and then get your alkalinity up. You kind of want to spend some concerted time on this if you can. It sounds like you're working during the day, but you kind of need to get this done otherwise you're just going to drag out the process. Anyone home who can test, measure and add chems?
 
JoyfulNoise said:
An overnight loss of 0.5ppm is acceptable. During the day, you are fighting against the Sun and heat mainly. In a typical, clean pool, it is not uncommon to see FC losses of 2-3ppm during the daytime. You are in Dallas, TX, where it is blazing hot right now, correct? Well, if the pool is hit with sun all day and your CYA is on the low side, then between fighting organics, algae growth (algae is ALWAYS trying to grow) and UV, losing 4ppm is not out of the realm of possibility. This is why we need to nail down your CYA number too.

Get the pH down as best you can to 7.6 (it's going to want to rise quickly) and then get your alkalinity up. You kind of want to spend some concerted time on this if you can. It sounds like you're working during the day, but you kind of need to get this done otherwise you're just going to drag out the process. Anyone home who can test, measure and add chems?
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Yes, I'm in Dallas, so it is blazing hot here now. The pool gets a little shade during the day but is mostly in the direct sun between the hours of 9:00am and 5:00pm. I'll keep working on the PH - you're right that it goes up fast. I measured a 7.8 last night and it was back up above 8.2 this morning.

My FC level was at 10.0 last night (overshot the bleach addition a little, it seems), and then it dropped to 8.5 this morning, so a loss of 1.5 ppm overnight which isn't as good as the previous two nights. My test last night could have been a touch off, though, as I got home quite late and was in a hurry.

I can have my wife help with measuring and adding FC during the day - I'll show her how to do the tests this evening. I'll also get the CYA number today. Thanks.
 
Ok, here's the rundown from today (Thursday):

FC - tested at 8.5 this morning around 7:00am. When I got home from work and tested at 6:00pm, it was down to 2.5 ppm, so I lost 6 during the day. (I had a mixup with my wife on adding bleach during the day, she'll be doing that going forward so we don't dip below 5 ppm or so). I added bleach and tested again tonight at 11:00pm and got 8.5, so we'll see what it drops to overnight.

PH - you're right that this one keeps wanting to shoot up. I keep measuring at 7.7 or 7.8, and then within 12 hours it will shoot back up to over 8.2. I'll just keep watching and adding acid to keep it close to 7.6 until it stabilizes.

CYA - I measured tonight and it registered at about 25. The dosage I added a few days ago was supposed to be enough to take it to 40, so we'll see how much it keeps rising I guess.

Two other things from today - first, when I went out to test at 11:00pm tonight, I noticed that we're getting a ton of that cotton-like stuff that falls out of trees in our pool. Here's a picture from tonight (the cotton is all that stuff that you can sort of see floating on the surface). Would this be burning up any of my FC overnight each night?

Cotton.jpg

Also, when brushing today, I noticed a single tile that has some white discoloration. Below is a picture. I'm talking about the big white spot/streak. The horizontal portion of it lines up exactly with the water line, but this is the only tile that has this in the entire pool. I tried to brush it off with my nylon brush but it didn't really do much. Any idea what this might be and if I should be worried about it?

TIle scale.jpg

Thanks again for all the help!
 
I'll go in reverse order -

1. Looks like calcium scale coming from the grout. Weird to have just one tiny little patch like that. Are the tiles new or newly regrouted? In any case, if you dilute a little muriatic acid in a spray bottle (4 parts water to 1 part MA), and gentle spray it and rub with a small nylon brush or toothbrush in that area, it should come off.

2. Get that fluff out of the pool. It's probably not a huge demand on your FC, but any gunk the FC has to oxidize is FC that isn't fighting off algae. Time to make the kids earn their keep and get out there with the skimmer pole and leaf rake :D

3.CYA is lower than I expected. Ok, wait the full week and retest. If it's not up by then, add enough to raise it by 10-20ppm and wait and see what happens. I don't like it when the CYA misbehaves and we want to be careful and not over stabilize the pool.

4. pH is going to be your biggest bear to slay while your plaster is curing. Just try to keep it down as best you can. Remember that bleach has excess lye in it so it raises the pH as you add it. Try to test and adjust your pH while the FC is low and get your pH set before adding the bleach.

5. FC - well, your water is definitely eating up the chlorine. Let's just keep at it as you're doing it now and we'll fight the great green algae monster after the curing is over. Sunlight and heat are also a big factor here as well as your low CYA. All of that is combining to tear through the FC.

Hey, what about TA? Where's the TA at??
 
Ok awesome, thanks. I'll get that calcium scale off tonight. The tiles are all new (when we bought the house a couple of weeks ago we had new plaster, new tile, and new flagstone done). And I'll continue to skim the fluff off - it just became apparent last night when I went out to get a test sample how much was probably going in each night. Luckily, my toddler thinks it's fun to skim the pool with a net :)

Makes sense on the CYA and bleach. And I'll test the TA tonight when I get home (I'll do a full battery of tests and post the results).

The FC is interesting. I tested this morning around 7:00am and it was at 7.5, down from 8.5 at 11:00pm last night, so I only lost 1 ppm overnight again. I guess that's just on the cusp of what algae might look like? I seem to now be losing way more during the day so it will be interesting to see what my CYA reads in a couple of days. And I'll make sure to have some bleach added in the middle of the day to keep FC above 5, at least.
 
lvrpl said:
Ok awesome, thanks. I'll get that calcium scale off tonight. The tiles are all new (when we bought the house a couple of weeks ago we had new plaster, new tile, and new flagstone done). And I'll continue to skim the fluff off - it just became apparent last night when I went out to get a test sample how much was probably going in each night. Luckily, my toddler thinks it's fun to skim the pool with a net :)

Makes sense on the CYA and bleach. And I'll test the TA tonight when I get home (I'll do a full battery of tests and post the results).

The FC is interesting. I tested this morning around 7:00am and it was at 7.5, down from 8.5 at 11:00pm last night, so I only lost 1 ppm overnight again. I guess that's just on the cusp of what algae might look like? I seem to now be losing way more during the day so it will be interesting to see what my CYA reads in a couple of days. And I'll make sure to have some bleach added in the middle of the day to keep FC above 5, at least.
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Look forward to seeing the latest test results.

So and OCLT with 1.0ppm is basically right on the hairy edge of OK. You'd rather see it at 0.5ppm or 0ppm. Losing lots of chlorine during the day, considering sun, heat and low CYA is not unexpected. You'll be through your plaster sure soon enough and then you can SLAM the pool water. If it remains clear and your CC's are low (you should be testing and posting CC values too), then it will likely be a very short SLAM.
 
JoyfulNoise said:
Look forward to seeing the latest test results.

So and OCLT with 1.0ppm is basically right on the hairy edge of OK. You'd rather see it at 0.5ppm or 0ppm. Losing lots of chlorine during the day, considering sun, heat and low CYA is not unexpected. You'll be through your plaster sure soon enough and then you can SLAM the pool water. If it remains clear and your CC's are low (you should be testing and posting CC values too), then it will likely be a very short SLAM.
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So for expectations, should we be planning to not be able to swim in it until after we do a SLAM, which would have to be 30 days after the plaster finished? (We filled it on July 22, so that would mean another ~3 weeks until then, if that's the case.) Or is it possibly ok to swim if we keep getting OCLT tests at 1.0 or less loss?
 
lvrpl said:
So for expectations, should we be planning to not be able to swim in it until after we do a SLAM, which would have to be 30 days after the plaster finished? (We filled it on July 22, so that would mean another ~3 weeks until then, if that's the case.) Or is it possibly ok to swim if we keep getting OCLT tests at 1.0 or less loss?
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People do swim during a SLAM as it is safe to swim up to shock chlorine levels. However, the higher chlorine levels can be harder on the skin, clothing, etc, so it's best to wear some goggles and rinse off right away as well thoroughly wash bathing suits. But you can swim during a SLAM. I suspect if things keep progressing the way they are now, your SLAM is going to be a short one (a couple of days). But let's cross that bridge when we come to it.
 

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I just tested the TA and got 60. I'll get that up a bit more. PH also spiked back up above 8.2 so I'll add some acid.

On the FC front, it looks like I lost about 7.5 ppm during the day today. I'll let report back with how much we lose overnight tonight.

However, the cotton problem is becoming a bit ridiculous and overwhelming. It's like, all of a sudden 3 days ago, it started raining cotton from the trees. When I'm out trying to skim it (which doesn't work very well and doesn't clean off of my net very well), i'll pull one scoop out with a net while I watch 10 other pieces fall into the pool. I'm losing the battle and there's a lot of cotton starting to accumulate on the surface of the pool. It's really frustrating. Any idea what might work well to deal with that?
 
You need to keep a closer watch on that TA. 60ppm during a plaster startup is way too low. Please adjust your pH back down to ~7.8 and then add enough baking soda to get your TA back up again. TA is important as it is the main source of carbonate that the plaster needs to properly cure.

As for the white stuff, wow, what kind of trees are we talking about? There are different types of leaf rake bags you can buy that are smaller mesh sizes. That might help. What about your skimmer and pump basket, are those clean? How's your filter pressure, are you keeping an eye on that as well?
 
I'll get the TA up and test it regularly. On the plus side, I didn't lose an FC overnight (tested 8.5 last night and 8.5 again this morning).

I think the white stuff is coming from some cottonwood trees, or at least some sort of poplar. Our house backs up to a large undeveloped area with a creek and full of trees (and snakes, wasps etc...), although it's apparently getting developed later this year. I check the skimmer and pump basket daily and clean them out every two or so days. Filter pressure is fine also, although will likely need a backwash in the next week or so (will do a full teardown most likely, actually).

I'll check out some of those other leaf bags, but I think a finer mesh might make it worse. The white stuff gets caught in the net - that's not the problem. It's that it's so light and fluffy that pushing a net towards it moves enough water to also push the fluffy stuff away from the net. It's really maddening. And as soon as you get it out, 10 more fluff balls come raining down. I'm hoping this only lasts a couple of weeks or I might go crazy.
 
Yup, I hear what you're saying. There are times throughout the year where a mesquite tree near my pool just dumps loads of fine pollen and flowers into my pool. I do my best to grab what I can with the leaf rake and the skimmer catches the rest. I use a nylon skimmer sock in the skimmer basket and it gets loaded up with particles. During the high pollen season, I empty it daily and dump out about a pound of junk each time.

Have fun with the filter tear down....it'll be "educational" for sure ;)

Glad to hear the FC is holding overnight, that's a good sign. Keep up on the pH and TA. I know it's exhausting, but your plaster is thanking your for it. Oh, and when you get a chance, post a picture of your pool. It's always nice to see pictures.
 
So some good news - FC loss has been zero for the two nights. We're still losing a lot during the day (6ppm to 8ppm), but it's been crazy hot and I tested my CYA a couple of days ago and it was low (~25 or ~30). I added some more CYA yesterday to get it up to 45 or so, so hopefully the FC loss during the day will get better.

PH is a constant struggle - I'll get it down to 7.6 or 7.8 every morning, and then it's back up to over 8.2 by the next morning usually. I tested TA tonight and it's at 90 - do you think I should bump that up some more?

Pictures - sure! Check out this thread of the remodel: http://www.troublefreepool.com/threads/101244-Opinions-on-tile-plaster-coping-selection
 
Ok. So your CYA is definitely too low for your location. Definitely get it up to 50ppm.

For TA, if you need to increase it without increasing pH, then use baking soda. That will raise TA and not pH.


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Good to hear about your FC holding overnight. That's a very good sign.

Remember, you only keep your TA up for the first month and then you can bring it back down. By the way, how many days has it been?


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No FC loss again last night. And the FC loss during the day was much less yesterday (we lost 4.5 instead of the 7-8 ppm during the day we had been losing). I wonder if it was that extra CYA I put in two days ago. I guess we'll see how much FC we lose during the day today.

Gotcha on the TA - it's been 15 days since we filled it, so halfway there. If the FC continues to hold overnight without more than a 0.5ppm loss, do you think we should still do a SLAM after 30 days? And if we get a good run of nights with no FC loss, would you think it's ok to swim? Or should we still hold off on swimming until after the 30 days and a SLAM, regardless of how many days in a row we may or may not get with no FC loss overnight?
 

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