How to Increase CYA

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It's very strange then. We've obviously heard of liquid chlorine degrading, but I've never heard of it increasing more than it should, unless there was another chlorine source that wasn't accounted for, or the pool measurement was off. But if all of your other additions are changing as needed....

I guess chalk it up to good luck and move on?

The only other thing I can think of is that the testing is maybe off and you might be using the wrong multiplier for the drops you're testing? This may have already been suggested and if so, I apologize. What sample size are you using and what are you multiplying your final drops by?
 
PoolStored said:
^^^What are these measurements? Can you post a picture of the entire pool?
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As I said, it's an odd-shaped pool, so I made several calculations which range from overestimates to underestimates, just to be sure I covered all bases. At the time I was thinking that once I had all my possible capacities it would be better OVERestimate since having too much FC would be better than having too little in my quest to battle algae which had been plaguing me. And, like most folks, is why I initially came to this forum.

That said, here's how I arrived at my figures. As you can see by the pic, this is not a standard pool. It is not even kidney-shaped. It's more like a rectangular organ with tumors, which makes it hard to measure. Depending on where I take measurements, length ranges between approximately 33' and 35', and width ranges between approximately 15' and 20'. Shallow end is 4', deep end end is at least 8' (couldn't measure exact middle of deep end). I do realize that curves can negatively affect capacity, hence why I took conservative calculations into consideration (as best as I could), as well.

20230501_174900.jpg
Calculations:

1) 33 x 19 x 6 x 7.5 = 28,215 used widest point
2) 33 x 15 x 6 x 7.5 = 22,275 used narrowest point
3) 32 x 19 x 5.75 x 7.5 = 26,200 more conservative on length and depth to try and accommodate for weird shape

4) Combo 1
Shallow: 20 x 15 x 4 x 7.5 = 9,000
Deep: 17 x 16 x 8 x 7.5 = 16,320
9,000 + 16,329 = 25,320

5) Combo 2
Shallow: 21 x 14.5 x 4 x 7.5 = 9,135
Deep: 17 x 18 x 8 x 7.5 = 18, 360
9,135 + 18,360 = 27,495

I chose #5 to base my initial chemical dosing requirements on, to be safe, and initially added lower than recommended amounts, followed by testing, and adding more if necessary, to see what I really needed. I logged everything. That's how I know, for example, that Poolmath is dead on with my Muriatic acid needs.

Interestingly, until this year, I never even questioned Poolmath chlorine dosage recommendations, and just added what it recommended. Only this year have I really paid attention, and noticed that I need much less chlorine.

I've never added calcium or CYA (intentionally) before. But we had 12 atmospheric river weather systems hit us in 3 months this winter. Each of them is supposed to contain more water than the Mississippi River! And, I believe it, based on the rain we got. When those weather events hit, many of my neighbors were draining their pools with hoses, so I knew my pool had to be draining a lot of water through my overflow port. I kept my pool pump going as usual, as well as my cleaner, so I know my water was well mixed while it was raining and draining. It makes sense to me that my CYA and CH content plummeted. When I went to add them back in, I was told to add significantly less than the dosage recommended, and monitor changes before adding the rest. I noticed that I needed to add less than the recommended dosage amounts. I didn't think anything of it, and just thought it was a nice little money savings. Now, while I was monitoring those additions so carefully, I was also being diligent in keeping FC and PH in check, too. That's when I noticed the chlorine dosage discrepancy. I decided to play it safe and double-check my testing with Leslie's testing. Both report the same, so I know my tests aren't off. Algae has receded (pool pump died right before i added CYA and calcium - took 10 days for new pump to arrive and replace) and I only have a little of the black algae left, which is why I was being sure to keep FC on the high side to begin with. And my water is crystal clear.

I'm not complaining, by any means. I'm thrilled to have found TFP, and am happy that my water has never been better. I'm happy to use less chlorine. Less chemicals is better for me and my wallet! It's just odd that the dosage discrepancy is, in my case, so significant. Even if I use the lowest capacity based on calculation #2, chlorine recommended dosage is still way off. Like Marty alluded to, I would have to be off by way more than 50%. And, if I'm off, ok, someone please help me figure out what capacity I really have. If it's less, then great, theoretically more savings for me. But, I've been balancing my pool since I've been on here using a combination of Poolmath suggestions and adjusting and testing, so even if i find I have less capacity, it's likely not going to change what I'm using/spending now. But it would be nice to KNOW what I have. Knowledge is always a good thing to have. :goodjob:
 
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IceShadow said:
It's very strange then. We've obviously heard of liquid chlorine degrading, but I've never heard of it increasing more than it should, unless there was another chlorine source that wasn't accounted for, or the pool measurement was off. But if all of your other additions are changing as needed....

I guess chalk it up to good luck and move on?

The only other thing I can think of is that the testing is maybe off and you might be using the wrong multiplier for the drops you're testing? This may have already been suggested and if so, I apologize. What sample size are you using and what are you multiplying your final drops by?
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It is strange. As mentioned in the reply I just posted, I have double-checked my tests with Leslie's for what that's worth. But, I am testing as usual. Using 10 ml level and dividing my drops by two (multiply by .5 I think is how it's worded in the manual) like I always have.

I actually also considered this (reaching again):

B.TFP (before coming here), I used a 💩 TON of tabs (got to the point of loading 5 tabs in TWO floaters!). Not surprising, although I didn't know it, CYA at the time was like 150 or 200, or something like that. Anyway, what if some of that tab build-up residue got stuck in the old, worn out pool Plaster? Now my Calcium got low, right? And, water sucks calcium form Plaster. So, what if it also sucked out the tab residue? Of course, this is preposterous, especially because if that were to happen, then tests would show adequate, if not high, FC levels, and there would be no recommended dosage amount at all.

What's happening is that I only need to add a small amount, which I am totally fine with. I just wish I didn't have to add it it as often. Even every other day, would be easier. But, that's another thread in itself. :cheers:
 
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Once the dichlor dissolves, the CYA and FC are separate and not at all bound to the calcium, so I don't think that's a possible explanation.

What I was able to do in my climate might work for you. Try dosing up to the top end of the recommended FC for your CYA, and test it the next day. If it seems like the loss is enough that the same loss the following day won't take you below the bottom range of that recommendation (and thus nowhere near the minimum range) you might be able to cut back dosing to every 2 days. It worked in my climate, but may not in yours as you're closer to the equator than I am, and probably deal with more warm and sunny days than me. It may also work now, in the "shoulder" seasons, and need to go back to daily dosing in the summer.
 
Of course the residue in the plaster thing doesn't hold true; I just mentioned it to show how many mental exercises I've been going through in trying to figure out why I need so much less than the recommended dosage. And, I'm sure many of the veterans on here don't believe me, but I have no reason to lie, you know what I mean?

Regarding dosing higher, hoping not have to add chlorine less often, the time I added 9 cups to go from 3.5 to 8, the next day I was at 6, but didn't push it to see if I could get to 3 days without it dropping too low, because I didn't want to go below 5 as I was in the middle of getting rid of algae. Under normal circumstances, I likely can get 3 days out of one high dosing, maybe even 4 with a super high dose, during this time of year, the shoulder, as you put it. But, you and Marty are likely right, in that I might be hard-pressed to get more than two days in mid-summer.

So, how in the world do pool service people get by servicing a pool only once a week?
 
MrLeadFoot said:
C'mon, seriously? They can't possibly do all that. A homeowner would certainly see, and question, that, wouldn't they?

FWIW, I've never had a pool service. Prior to TFP, I just did it all wrong, all by myself. :brickwall:
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Seriously I'm not kidding. We rented a house in CA and our landlord had a "pool guy". I watched him do exactly what I said & watched Algae start. I took pics & told her to fire him and that I would maintain it.
 
Since the algae is now gone, you’ll use less. I’d try again and see if you can go longer by pushing to the max or your FC range and just checking the FC level over a couple of days.
 
MrLeadFoot said:
C'mon, seriously? They can't possibly do all that. A homeowner would certainly see, and question, that, wouldn't they?

FWIW, I've never had a pool service. Prior to TFP, I just did it all wrong, all by myself. :brickwall:
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I mean, it works for a while. Push the FC high enough (well above shock level), put in tablets, and by next week the FC is high enough that the pool isn’t green. It’s gonna be kinda murky and cloudy but hey, they shock it again and dump in (and charge you for) some clarifier, and you’re set.

Until the tabs push your CYA high and it does go green from the FC being ineffective. Then they just tell you the water is getting old and needs to be replaced so you should dump it and replace it. Then they can start the cycle again.

This is pretty standard.
 
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IceShadow said:
I mean, it works for a while. Push the FC high enough (well above shock level), put in tablets, and by next week the FC is high enough that the pool isn’t green. It’s gonna be kinda murky and cloudy but hey, they shock it again and dump in (and charge you for) some clarifier, and you’re set.

Until the tabs push your CYA high and it does go green from the FC being ineffective. Then they just tell you the water is getting old and needs to be replaced so you should dump it and replace it. Then they can start the cycle again.

This is pretty standard.
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I used to be that guy, on my own pool. Like I said earlier, my CYA ended up being so high that eventually I was floating 10 tabs, and still getting algae. I never got the kind that made the water cloudy or green, though, just the yellow and black algae, and I was constantly fighting them. The beginning of the year was always when my pool had the least algae, I think because winter rains would dilute the pool so MUCH, via self-draining, that the CYA would drop just enough to make the tabs effective again, for a while. At least, that's my theory. By summer I was back to fighting algae.

But, I was the typical homeowner who didn't know better. A pool service should know better. Based on the science promoted by TFP, do you mean to tell me that there is absolutely no way a pool service can provide the proper care and maintenance unless they come every other day (SWG pools notwithstanding)?
 
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BTW, I've been adding chlorine at night, under the presumption that because there is no sun to burn it off, it will provide more killing time overnight, before it burns off during the day, whereas I feel like if I add it in the morning, it won't be as effective because it burns off too quickly. Is that right? If so, does increasing the dose in the morning compensate for burn off, or is that just wasting chlorine?
 
MrLeadFoot said:
do you mean to tell me that there is absolutely no way a pool service can provide the proper care and maintenance unless they come every other day (SWG pools notwithstanding)
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Exactly. In the peak season most pools lose 4 ppm a day so they need 28 FC weekly. But chlorone burns off as a %, so it does so faster at higher level and the 28 FC is gone in 4 or 5 days instead of 7. It really becomes noticeable in the 20s. It would also bs rather expensive to waste that much FC on a weekly basis.

Customers won't pay for multiple visits a week when 'the other guy' only has to come once. Clearly he is much better at it, you see. And so starts the cycle of underwriting and overcorrecting. When it goes south, they seek out a different company, expecting different results.
 
At this time, I think I need to issue an apology to the OP for hijacking his thread and making it about FC when it was supposed to be about CYA! :rant:

Seriously, I thought I would just ask about chlorine on the same post because it would be easier for everyone to see the context in which I was asking. In hindsight, I think I should've started a different thread, because now when someone searches the forum looking for answers for CYA or Chlorine they might think they're getting some unrelated results. Sorry, everyone.
 
Nah, it's all good. It's more about your pool anyway. :) Thread drift happens, and so long as it's not someone else's thread, then it's no big deal.
 
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mknauss said:
As the sun angle climbs, increasing your CYA to 50 ppm or so will help on FC loss.
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Just wanted to let you know that I am already seeing what you were talking about. You see, at the time we were talking about all this we had days with a mix of clouds and sun, and the days were a bit shorter. I was only needing to add 2-3 cups of LC daily. Now, only a few weeks later, we are having sunny, longer days, and I am already needing to add double that amount, and have had to add 5 cups a day.

Also, when I added originally added stabilizer I tested CYA two days later, and got 30-35. I tested yesterday, and it is now a solid 40. I don't know how it went up, but I wonder if some of the stabilizer hadn't fully dissolved in two days so my test was a little low. In either case, I'm going out of town in a couple of weeks, so my thoughts are to not add stabilizer right now, and to instead first float two trichlor tabs while I'm gone, then test CYA to see if they might raise my CYA so I don't need to add stabilizer to get to 50. Am I thinking right here?
 
Summarizing a few thoughts:

- This winter/spring in Northern CA has definitely been interesting. You probably drained or auto-drained a lot of water through the winter (I estimate I drained 8-10"), which is part of the explanation for CYA loss and other values dropping. However, as noted CYA does degrade somewhat over time; even in the dry years where I end up draining 0" I need to bump it up in the spring. Typically that's a once a year adjustment.

- Similarly, if the chlorine add measurememts are from the past couple weeks, that was quite a cooldown we had -- 3 weeks ago I put the cover on, knowing that we'd be swimming by the end of April, and it got close to 80...and then 2 full weeks of cloudy, rainy, cool to downright weather had it back below 70 before it's finally up again the last couple days. Not at all surprised that your FC usage was a lot less than normal too.

- Once you're comfortable and committed to maintaining your FC levels, bumping CYA to 50ish will reduce usage by enough that you *might* be able to go to every other day FC additions -- but think of that as opportunistic. You can set an upper FC target a bit higher (below 10ppm so it doesn't affect the pH test), and see how long it stays well above the minimum. But test every day until you're 100% sure of the pattern; the key is to NEVER let FC go below minimum at any point in the day.

- As mentioned, it doesn't matter when you add chlorine; it dilutes into the water right away. There shouldn't be anything for the FC to be killing overnight anyway -- one of the key tests for a healthy pool is an overnight chlorine loss teest (which should be effectively 0).

- We do NOT recommend the "CYA on a snake" method, so don't do that again :) That made me remind myself to ALWAYS turn on the pool light before doing anything in the dark!

- CYA on a sock works well for me -- I have a 1x2 stick, probably 3' long, with a string on one end, and a brick to hold the other end, so I can hang the sock away from the wall in front of the return. I sacrifice a white athletic sock for the cause. Granulated CYA seems to vary greatly -- I've had some tubs/bags that took a couple days to dissolve, and others that squished out in a few hours, all at the same temperature. It doesn't go bad, so keeping the rest of a 4-5lb bag around isn't a bad thing.

- Because we get no rain replacement over the summer, unless you have huge amounts of splashout you may not need to test all of the levels as often. For example, I test CYA 3-4 times while getting it right in the spring, then maybe once or twice the rest of the summer then not much over the winter. Similarly, I only test CH and TA every month or two (if even), since they don't change much over time. That might reduce the test reagents needed enough to make you comfortable doing it yourself, which we always recommend. It sounds like you have had reasonably accurate pool store tests, so that's good but could vary if new employees come in etc. And, like a timeshare presentation, you will get their "recommendations" for better or worse. Around here I haven't found pool stores to be too pushy about their products/method if you come in looking like you know what you're doing, but I know in other places they are.
 
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