Do you backwash your pool? Or need to add water? This could account for the CYA difference.
[emoji176] Lisa P.
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[emoji176] Lisa P.
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CYA - liquid or powder, or raise with Pucks
- Thread starter bbrock
- Start date
Since I have been using the solar pool cover since May, I've only had to top off two times, maybe three at the most. I am performing the test the same each time, it's just odd to me how I could've consumed CYA in one month to bring it from 30 to 20.
I added 26 ounces of CYA in a cut-up t-shirt to the skimmer to bring it from 20 to 30. Once at 30, perhaps I will try a dry run with some pucks and bringing my chlorine to shock to see if it will get me through 7 to 9 days.
I added 26 ounces of CYA in a cut-up t-shirt to the skimmer to bring it from 20 to 30. Once at 30, perhaps I will try a dry run with some pucks and bringing my chlorine to shock to see if it will get me through 7 to 9 days.
Any opinions on my vacation plan of managing the FC by bringing to shock level & using pucks?
Also, if Pool Math shows one 8 oz puck will raise CYA 1.8, and FC by 2.9, but of course that's if it's completely dissolved, right? I'm just trying to figure out how much 4 pucks would add daily to maintain my FC. With the solar cover on, I average about a loss of 1 ppm of FC daily, possibly 2 at worst case. I would bring to shock level 16.
Also, if Pool Math shows one 8 oz puck will raise CYA 1.8, and FC by 2.9, but of course that's if it's completely dissolved, right? I'm just trying to figure out how much 4 pucks would add daily to maintain my FC. With the solar cover on, I average about a loss of 1 ppm of FC daily, possibly 2 at worst case. I would bring to shock level 16.
I have no experience with pucks, but I know many people use them for vacation. As long as you know exactly what they do to your water, you should be good.
[emoji176] Lisa P.
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[emoji176] Lisa P.
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Tx Lisa. I just don't know how to determine what they would add in terms of FC on a daily basis for approx 7-9 days. I usually lose about 1, maybe 2 ppm FC. If I start at shock level 16 ppm FC, of course I will lose more when it is higher. But, I just don't know how much the puck will be adding daily to offset my daily loss.
When away from my home and pool, for a puck holder, I use a plastic peanut butter jar with slits on the sides and small holes on the bottom. It is held on the outside of my pool ladder, about a foot from the surface, with removable/reusable zip ties.
If you measure the weight loss of the 3 inch pucks every 24 hours, you can calculate the rate of dissolution. If you know your typical FC consumption/day, you can calculate the number of pucks to replace the consumed chlorine. I require about 3 pucks to arrive at a 1.5 ppm/24 hours replacement rate in a 42,000 Liter pool. Take care in mounting the jar away from vinyl pool surfaces, as the concentration may increase locally, during periods when pool circulation is off.
This approach is very approximate, since the dissolution rate is a function of puck surface area, which decreases and so will not be linear with time. I keep my pool covered when I am away, which also reduces chlorine loss.
If you measure the weight loss of the 3 inch pucks every 24 hours, you can calculate the rate of dissolution. If you know your typical FC consumption/day, you can calculate the number of pucks to replace the consumed chlorine. I require about 3 pucks to arrive at a 1.5 ppm/24 hours replacement rate in a 42,000 Liter pool. Take care in mounting the jar away from vinyl pool surfaces, as the concentration may increase locally, during periods when pool circulation is off.
This approach is very approximate, since the dissolution rate is a function of puck surface area, which decreases and so will not be linear with time. I keep my pool covered when I am away, which also reduces chlorine loss.
The 26 oz of CYA that I had in a piece of shirt in the skimmer has now all dissolved. It may have already been stated, so sorry if duplicate question. After a CYA addition, how long do I have to wait before testing?
ChemGeek, you had stated "With this technique, the CYA should mostly measure in the test pretty soon after it is dissolved." Would you happen to know more specifically?
ChemGeek, you had stated "With this technique, the CYA should mostly measure in the test pretty soon after it is dissolved." Would you happen to know more specifically?
Tx. Perhaps I should wait though. No need to waste testing reagent if it won't show up yet. I was originally going to add enough to raise from CYA 20 to 40, but that would have meant 52 oz of CYA. I only added 26 oz at this time in skimmer. Glad I just did that b/c 53 oz would have been too much I think to do at one time. The 26 oz in the piece of t-shirt was already a big amount in my skimmer, and with the skimmer on 24/7 it still took 4 days to dissolve. Regardless of being at CYA 20, 30, or 40, I have already been playing it safe though and basing my chlorine additions on a CYA of 40. For the past week or more, my FC extinction has only been averaging 0.5-1 ppm/day. I assume I will see more extinction when my CYA increases.
I think just adding enough to raise to CYA 30 is good for now b/c we intend to go on some vacations in Aug. and Sept. I have some pucks to use for that time in addition to bringing my pool to shock level. I am still curious though does anyone know exactly how much one 8 oz 3" puck will raise my FC level on a daily basis? Pool Math shows that it will raise it by 2.9, but that would only be if it is completely dissolved, right? Is the only way to figure this out to do the test and bring to shock of 16, add four pucks to my floater, and then test daily to see how my FC level manages?
I think just adding enough to raise to CYA 30 is good for now b/c we intend to go on some vacations in Aug. and Sept. I have some pucks to use for that time in addition to bringing my pool to shock level. I am still curious though does anyone know exactly how much one 8 oz 3" puck will raise my FC level on a daily basis? Pool Math shows that it will raise it by 2.9, but that would only be if it is completely dissolved, right? Is the only way to figure this out to do the test and bring to shock of 16, add four pucks to my floater, and then test daily to see how my FC level manages?
- Jun 12, 2011
- 3,767
- Pool Size
- 19500
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pureline Crystal Pure 60,000
CYA can take up to a week after its added to show up on testing. How much one puck adds depends on the weight of the puck and volume of your pool. The pucks I have are 7.2 oz. each. In my pool volume each puck will: raise FC 2.5, add 1.5 CYA, lower the pH .14 and add 2.1 to salt. I have that written on the top of the container holding the pucks, for quick reference.
Your plan for keeping the CYA on the low side to allow pucks for vacation is aa good one.
Your plan for keeping the CYA on the low side to allow pucks for vacation is aa good one.
The CYA taking a week to show up is mostly when it is added in the skimmer and caught in an oversized cartridge filter. The reason is that the CYA granules get caught in the filter and the water velocity there is VERY slow so they take a long time to dissolve. If you have the CYA in front of a return or in a sock, pantyhose, or T-shirt in the skimmer with the pump running, then the fast water flow not only dissolves the CYA more quickly, but does so mostly in place rather than in the filter. I've done this many times and always get a full or nearly full CYA reading within a day after the CYA is no longer visible in the T-shirt I use in the skimmer.
Bumping this old thread to ask a few questions! 
I'll be honest with you guys: I don't test CYA often. In fact, the last time I officially checked it until now was back in September 2016! After partial refills and rain-drains, down from 135(!), it has always been 50-60 (erring on the side of 60). Theoretically it's not supposed to reduce on its own, so I just got lazy in the testing...
I'm using an automatic Stenner pump chlorine feeder, but found myself wondering why my daily FC-loss was exceeding my calculations and tests. So I decided to retest my pool's CYA. Low and behold, it was only 25! With the increasing solar intensity here in Phoenix, the sun was cooking off my chlorine!
I have a few 3" pucks left over from before going BBB, so I tossed two (2) into Deck-Chlor feeder. CYA now seems to test at 30-35, leaning towards 30. Having only 3 pucks left, which I would like to keep to use in my fountain (I chop them into quarters and put the quarter into a glass jar with a plastic top with a small hole in top of it), I decided to go to the pool store to buy some CYA granules.
The mom 'n' pop pool shop guy behind the desk asked a few questions to make sure I knew what the stuff is but proceeded to say that "new research has shown that the best value for CYA is 35." I asked to clarify if "35" is okay even for a pool here in Phoenix, where the sun will obliterate anything in its path (refer to the scene in The Chronicles of Riddick for more information). He said, "yes." Should I believe him? From what I've read here, the ideal number is 50, maybe 60 in super-hot-and-sunny areas like the Southwest. Please clarify because I bought a 5-pounder of CYA for $16 plus tax. Thanks!
CYA scares me because it sucks. I don't want to overdo it and go over the 50-60 mark.
I'll be honest with you guys: I don't test CYA often. In fact, the last time I officially checked it until now was back in September 2016! After partial refills and rain-drains, down from 135(!), it has always been 50-60 (erring on the side of 60). Theoretically it's not supposed to reduce on its own, so I just got lazy in the testing...
I'm using an automatic Stenner pump chlorine feeder, but found myself wondering why my daily FC-loss was exceeding my calculations and tests. So I decided to retest my pool's CYA. Low and behold, it was only 25! With the increasing solar intensity here in Phoenix, the sun was cooking off my chlorine!
I have a few 3" pucks left over from before going BBB, so I tossed two (2) into Deck-Chlor feeder. CYA now seems to test at 30-35, leaning towards 30. Having only 3 pucks left, which I would like to keep to use in my fountain (I chop them into quarters and put the quarter into a glass jar with a plastic top with a small hole in top of it), I decided to go to the pool store to buy some CYA granules.
The mom 'n' pop pool shop guy behind the desk asked a few questions to make sure I knew what the stuff is but proceeded to say that "new research has shown that the best value for CYA is 35." I asked to clarify if "35" is okay even for a pool here in Phoenix, where the sun will obliterate anything in its path (refer to the scene in The Chronicles of Riddick for more information). He said, "yes." Should I believe him? From what I've read here, the ideal number is 50, maybe 60 in super-hot-and-sunny areas like the Southwest. Please clarify because I bought a 5-pounder of CYA for $16 plus tax. Thanks!
CYA scares me because it sucks. I don't want to overdo it and go over the 50-60 mark.
No, do not believe him. Sweet spot for me is 30 to 50. Pool is manageable/happy at those numbers. I keep it at 30 right now. When I'm vacationing w/ or w/out a pool sitter, I'll throw three pucks in my floater. If the level goes up to 50 later in summer it's cool because I could still manage it. After this winter, level is back down to 30.
Keep the granules, throw them in a piece of cut up shirt with a knot or a rubber band around the top, and throw that into the skimmer basket. Keep the pump on 24/7 until they are dissolved. If you have a variable speed pump, no sweat because you could just kick it on a low rpm.
Keep the granules, throw them in a piece of cut up shirt with a knot or a rubber band around the top, and throw that into the skimmer basket. Keep the pump on 24/7 until they are dissolved. If you have a variable speed pump, no sweat because you could just kick it on a low rpm.
No need for liquid cya, unless you have money to burn/waste. Granular is fine. eBay has some great rates for bulk cya. If you have pucks, use them till you get the cya level you need.
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