Imagine how a newbie like me deals with the disappearing CYA game! Last winter, my CYA played peekaboo (20-25). And then yes, we had a ton of rain this early summer. I started with a CYA=50 in April (I never added any CYA after those winter numbers). I'm thinking I'm set for the summer!! 4/25 and 4/30 two vac to wastes. June 16 T.S. Bill hits Houston, another vac to waste. I added two pucks thinking that would be enough. 7/3 CYA= 0 (less than 30?). So I add 3 lbs dichlor on 7/3, and three pucks before OOT Vaca on 7/5. At the most I thought total added since April reading was ~12 ppm CYA. 7/17 CYA = 70! Where did I add/calc wrong please? I plan to retest CYA tonight.
I don't CYA what I'm doing wrong.
- Thread starter 8corneflakes
- Start date
I would first like to thank all the folks that have assisted me in maintaining my pool. This is my first post but I've been reading up daily.
I am in the same boat with the disappearing CYA. I truly believe that CYA indeed depletes overtime much more than understood. I believe Chemgeek covered this in some of his posts. With that being said my pool gets over 8 hours of sun a day. I try and keep my CYA around 30-40. I have an all Hayward System. Salt Water, filter cartridge and pump. I have a 14700 gallon Vinyl pool.
My test results (using Taylor Kit) as of this morning are as follows:
PH: 7.5
FC: 1.8
CC: .2
CH: 275
Alkalinity: 110
Salt: 3300
Pool Temp: 88-90F
Aquarite cell: Set at 70% was 45% up to last week
Solar Cover: Yes, clear
Variable Pump: Yes run 13 hours a day in order to turn over 1.5 times.
My PH doesn't drift too much only added a small does of MA once this season. The past two weeks on Long Island have been the warmest of the season thus far. Started the season with ZERO cause it was a new pool built in October and CYA was never added. I was at 40 on my CYA in May and June. July i cant read above 30PPM. There is definitely some CYA in the pool (my guess around 20-25) but i am chasing it by adding 10PPM here and there. In total i have added 7 pounds this season which equates to 58 PPM (roughly). So if I am reading 25 currently where has the other 33 PPM gone? I have only added water to my pool twice about an inch each time and we haven't received a lot of rain this spring/summer. My chlorine use in a 24 hour period has gone from 2PPM to around 3.1-3.3PPM. Certainly not terrible and I believe its a combination of factors, (Higher air temp, higher pool temp, lower CYA levels, etc.). MY CC has always been below .5, usually around .2 -.3 which i attribute to the constant use of the solar cover.
I am in the same boat with the disappearing CYA. I truly believe that CYA indeed depletes overtime much more than understood. I believe Chemgeek covered this in some of his posts. With that being said my pool gets over 8 hours of sun a day. I try and keep my CYA around 30-40. I have an all Hayward System. Salt Water, filter cartridge and pump. I have a 14700 gallon Vinyl pool.
My test results (using Taylor Kit) as of this morning are as follows:
PH: 7.5
FC: 1.8
CC: .2
CH: 275
Alkalinity: 110
Salt: 3300
Pool Temp: 88-90F
Aquarite cell: Set at 70% was 45% up to last week
Solar Cover: Yes, clear
Variable Pump: Yes run 13 hours a day in order to turn over 1.5 times.
My PH doesn't drift too much only added a small does of MA once this season. The past two weeks on Long Island have been the warmest of the season thus far. Started the season with ZERO cause it was a new pool built in October and CYA was never added. I was at 40 on my CYA in May and June. July i cant read above 30PPM. There is definitely some CYA in the pool (my guess around 20-25) but i am chasing it by adding 10PPM here and there. In total i have added 7 pounds this season which equates to 58 PPM (roughly). So if I am reading 25 currently where has the other 33 PPM gone? I have only added water to my pool twice about an inch each time and we haven't received a lot of rain this spring/summer. My chlorine use in a 24 hour period has gone from 2PPM to around 3.1-3.3PPM. Certainly not terrible and I believe its a combination of factors, (Higher air temp, higher pool temp, lower CYA levels, etc.). MY CC has always been below .5, usually around .2 -.3 which i attribute to the constant use of the solar cover.
Missed my 1 lb dichlor addition on 7/10. But i still don't know how my CYA increased that much.
Today, we swam from 10-5. Had about 15 people swimming. 92 degrees and blazing sun. Started with 4ppm. Ended the day with .5ppm Probably acceptable.
My first posting. New to the forum this year. Just wanted to say that I too bought HTH stabilizer at Walmart. Put it in a sock and hung it in front of the return but have not seen an increase in my CYA yet (have tested twice since Friday). I was going to post a question myself on this and then saw this discussion. I have used 3 chlorinating tablets in the skimmer hoping to get a rise in CYA also.
Hmmmmm, could we be on to something here? I put in another 4 pounds today and it's all dissolved. I'm going to test next week and revisit this topic to post my findings. I'm not at all worried because I really have a handle on my water situation. I owe it all to TFP. I can just look at it and usually know what it needs. All you newbies, hang in there. You'll be there too, soon enough.
If you suspect that the product may not actually be CYA, you can do a simple test by crushing some granular CYA with a mortar and pestle to be a fine powder and then put 1/8th of a teaspoon in 1 gallon of warm water and mix thoroughly. That should be around 150 ppm CYA. Do your CYA test and if it doesn't measure any CYA then try using the 50 ppm CYA standard solution and if that measures correctly then the product you have is bad.
Cornflakes,
The CYA view tube only goes down to 20 ppm because the resolution is not much better than that. The K-2006 view tube only goes down to 30 ppm. I still believe you purchased something that did not contain adequate CYA. I would go get 'em.....at least for some free replacement.
Everyone else,
There are surely enough inconsistencies here to make me think CYA in your pool is not as consistent as we have assumed. I believe we should start testing CYA every 30 days or so.....even in the off-season if you don't close your pool. (Yay! refill sales!) For whatever reasons, as a group, we don't seem to be able to hold CYA like we once thought.
I know this will sound a little bit defensive but we have no really well documented cases of the Taylor Reagent (R-0013) going "bad". It is chemically inert so it just sits there on the shelf much like muriatic acid, waiting for you to use it.
The CYA view tube only goes down to 20 ppm because the resolution is not much better than that. The K-2006 view tube only goes down to 30 ppm. I still believe you purchased something that did not contain adequate CYA. I would go get 'em.....at least for some free replacement.
Everyone else,
There are surely enough inconsistencies here to make me think CYA in your pool is not as consistent as we have assumed. I believe we should start testing CYA every 30 days or so.....even in the off-season if you don't close your pool. (Yay! refill sales!) For whatever reasons, as a group, we don't seem to be able to hold CYA like we once thought.
I know this will sound a little bit defensive but we have no really well documented cases of the Taylor Reagent (R-0013) going "bad". It is chemically inert so it just sits there on the shelf much like muriatic acid, waiting for you to use it.
I agree with your post Dave. There are variables involved that when we attempt to quantify them the end result is not consistently duplicated for every pool owner. I believe that the sun, water temperature, air temperature and the waters chemistry play a role in CYA depletion. Some folks might have a more stable CYA reading during the course of the season. However I also look after other pools in my area and I am finding that the CYA number indeed doesn't hold all season long. I have great eyes and know how to use many test kits with Taylor being my favorite. I also don't believe the Reagent is the issue since I have eliminated that possibility. Simply put, I believe the Cyanuric Acid is working harder is some pools than others.
We have never said that CYA holds all season long. Even in a covered pool that is warm it loses 2-3 ppm per month without any splash-out, carry-out, backwashing, or other water dilution. The question is how much is lost additionally in full sun and possibly at higher pH and especially when a SLAM is done. These all increase possible degradation of CYA from chlorine. The question is by how much. A few people report up to 10 ppm CYA per month loss; others less. Once in a while you get someone with a larger loss in a shorter period of time which is very strange unless their FC got to zero. For others, if the FC gets to zero it does not take long for the CYA to drop -- it happened to me in just a few days as I reported back in 2009 in It Can Happen to Anyone - Zero Chlorine, CYA-->Ammonia and if one is lucky this conversion goes to nitrogen gas or nitrate with no additional chlorine demand.
This idea that CYA does not go away except from water dilution has always been an oversimplification and never really true. As noted in Degradation of Cyanuric Acid (CYA) written in 2008, CYA is slowly oxidized by chlorine. Even a low 2-3 ppm CYA per month translates into 10-20 ppm CYA over a 6 month season and that's pretty much a minimum at the low end in a covered pool. The 10 ppm per month seems to be less common while something in between seems the most common but of course gets complicated by actual water dilution that varies by pool. We've also seen 5 ppm CYA per month loss in spas due to their hotter temperature and have always said to touch up the CYA level once a month by switching to Dichlor for one day per month in the Dichlor-then-bleach method.
Also see the recent thread CYA level dropping where the FC was let go to zero at times and SLAMs were also done, both of which would explain CYA loss. In the last post in that thread I link to scientific papers that show why CYA is relatively immune to degradation even from hydroxyl radicals, but there is the possibility that those produced from breakdown of chlorine in sunlight may contribute to CYA degradation and there would be at least 10 times as much during a SLAM and even at regular FC/CYA levels a higher pH of 7.85 has about double the amount as at a pH of 7.5. We just haven't quantified this more precisely to how this translates into ppm CYA per month under each condition.
So I would not characterize this as anything new. We've had reports of people losing CYA during the swim season from the beginning. It's just never been quantified in detail and the over-simplification that CYA is simply not lost except by water dilution prevented people from looking at actual losses from any sources. This is the danger of over-simplification. It makes things much simpler for newbies, but prevents seeing what is real because it doesn't fit the paradigm of that over-simplification.
This idea that CYA does not go away except from water dilution has always been an oversimplification and never really true. As noted in Degradation of Cyanuric Acid (CYA) written in 2008, CYA is slowly oxidized by chlorine. Even a low 2-3 ppm CYA per month translates into 10-20 ppm CYA over a 6 month season and that's pretty much a minimum at the low end in a covered pool. The 10 ppm per month seems to be less common while something in between seems the most common but of course gets complicated by actual water dilution that varies by pool. We've also seen 5 ppm CYA per month loss in spas due to their hotter temperature and have always said to touch up the CYA level once a month by switching to Dichlor for one day per month in the Dichlor-then-bleach method.
Also see the recent thread CYA level dropping where the FC was let go to zero at times and SLAMs were also done, both of which would explain CYA loss. In the last post in that thread I link to scientific papers that show why CYA is relatively immune to degradation even from hydroxyl radicals, but there is the possibility that those produced from breakdown of chlorine in sunlight may contribute to CYA degradation and there would be at least 10 times as much during a SLAM and even at regular FC/CYA levels a higher pH of 7.85 has about double the amount as at a pH of 7.5. We just haven't quantified this more precisely to how this translates into ppm CYA per month under each condition.
So I would not characterize this as anything new. We've had reports of people losing CYA during the swim season from the beginning. It's just never been quantified in detail and the over-simplification that CYA is simply not lost except by water dilution prevented people from looking at actual losses from any sources. This is the danger of over-simplification. It makes things much simpler for newbies, but prevents seeing what is real because it doesn't fit the paradigm of that over-simplification.
well, then this solves my problem. At the beginning of the season when I'm so excited to open the pool, I work fervently to get the water to the perfect readings. Then, as the season moves on, I get lazy and don't check daily. Mostly because I'm so confident in my ability to bring my water back from the dead. Because of this confidence, I'm not worried at all about the water anymore. Yes newbies, you will be here someday. Subsequently, frequently, my FC falls to near zero. To be honest, I just 'know' that a couple jugs of bleach will bring me to the very high end of appropriate FC. Probably, adding these couple jugs is creating a zero to shock level FC. It does keep my water looking fine, and since I don't EVER get my beautiful hair wet, I generally could care less if the FC is a bit high. Especially since there are ALWAYS at least 12 kids in the pool at any given time. I get so busy with the kids and achieving the perfect even tan until one day when I open the pool and it's a teeny bit cloudy. Then I decide to get the ol test kit out and BAM, super low CYA. I had no idea, that zero FC and shocking had this affect on the CYA. Personally, now that I know the reason, I'm not going to worry about it. Also, I will cancel the hit I had out for the poor customer service guy at HTH. Hope it's not to late.
ChemGeek:
I should correct that statement I made in my previous post. What I was attempting to convey is that CYA will drop "larger" than most have an understanding of or what is incorrectly provided to be accurate on so many pool websites/ forums. When I state the CYA numbers will hold I mean within a range and not drop dramatically on a percentage basis month to month. To me its a very misunderstood topic especially outside this site. A lot of misinformation on the topic is out there.
I do agree with your above post and previous posts on the topic. I believe it's prudent to continue to explore the issue because there is still some posts on here from others that contradict what you and I as well as others have concluded. CYA needs to be monitored more or less according to YOUR pool and findings through the season and year over year. One shouldn't be alarmed if they are losing CYA month to month even if its outside some of the numbers you posted above, as long as their FC and other numbers are stable.
I should correct that statement I made in my previous post. What I was attempting to convey is that CYA will drop "larger" than most have an understanding of or what is incorrectly provided to be accurate on so many pool websites/ forums. When I state the CYA numbers will hold I mean within a range and not drop dramatically on a percentage basis month to month. To me its a very misunderstood topic especially outside this site. A lot of misinformation on the topic is out there.
I do agree with your above post and previous posts on the topic. I believe it's prudent to continue to explore the issue because there is still some posts on here from others that contradict what you and I as well as others have concluded. CYA needs to be monitored more or less according to YOUR pool and findings through the season and year over year. One shouldn't be alarmed if they are losing CYA month to month even if its outside some of the numbers you posted above, as long as their FC and other numbers are stable.