Jandy SWCG's "optimal" water conditions: why raise CYA?

[famousdavis]

"You're starting to believe, but I don't think you're quite there yet."

You're right. The proof (for me) will be how this forum's methodology holds up in *my* pool, right? But everyone here has convinced me that I don't have to blindly and ignorantly follow a local pool store's advice on how to care for my pool (for which I heartily thank you!). Moreover, you've raised an interesting, viable alternative that I'm willing to try -- keep up my CYA level, keep up my FC level, watch over my CC level, and shock only when the pool needs to be shocked. Doesn't have to be once a week. Doesn't have to be once a month, even. Just when I need it.

So, I'll give it a go. My "insurance policy" against algae, though, is that I'll still add a maintenance dose of polyquat each week. The relatively low cost of doing that gives me peace-of-mind. What I need to work out now is how much time the SWCG needs to operate to keep up the FC level. Over this week and next, I should be able to nail that answer down.

[Watermom]

Just an FYI (and somebody may have already told you this earlier in this thread -- I didn't take the time to re-read it) -------- polyquat will cause your FC to plummet. Then you'll have to add more chlorine to pull it back up.

[Flysurfn]

So, Cya of 30 and FC-1.5, running a SWCG/DE Filter 12hours a day on 50% isn't necessary?
I should raise CYA to 60 and FC of 3 with less time on the cell?

I must say this is a great forum...

[waterbear]

So, Cya of 30 and FC-1.5, running a SWCG/DE Filter 12hours a day on 50% isn't necessary?
I should raise CYA to 60 and FC of 3 with less time on the cell?

I must say this is a great forum...

NO, you should raise it to 80 and maintain the FC at 4 ppm. The difference between 60 ppm and 80 ppm has been determined to be significant and directly translates into better pH stability in a salt pool.

[BigTallGuy]

Thanks Evan. I appreciate your reply. I am embarrased, and publically admit you were right about the CYA. I must have read the Pool Info, Not the SWCG info. Please accept my apologies.

In my case a few years ago, the Problem with the CYA was on a Fresh fill. I drained my pool to less than 1 inch of water and refilled. After adding the CYA, and discovered the "high CYA Problem", I had the water tested at three different pool stores (before I ever heard of this Forum) and not one could find anything wrong with my pool chemistry. The unanimous consensus was high CYA as the cause of the eye irritation. I cannot explain how 4 Lbs. of CYA took me to readings in excess of 110 PPM in approximately 11,000 gallons of water, nor can I explain why draining 2/3 of the pool water (the following year) and refilling with fresh water took me to 100 ppm. But that pool and all its water and problems are long gone, so it will remain a mystery.

Yes I am a slow learner, I don't just go out and buy or do everything everyone tells me to until I investigate it. After all when your own children and grandchildren tell you that their eyes burn in your pool, I will err on the the side of caution. As far as the test kit is concerned, my old one was barely adequate, but wouldn't test CYA, so yes, I ordered the Taylor.

Thanks again Evan, and Peace.

Rick.

[waterbear]

Thanks Evan. I appreciate your reply. I am embarrased, and publically admit you were right about the CYA. I must have read the Pool Info, Not the SWCG info. Please accept my apologies.

In my case a few years ago, the Problem with the CYA was on a Fresh fill. I drained my pool to less than 1 inch of water and refilled. After adding the CYA, and discovered the "high CYA Problem", I had the water tested at three different pool stores (before I ever heard of this Forum) and not one could find anything wrong with my pool chemistry. The unanimous consensus was high CYA as the cause of the eye irritation. I cannot explain how 4 Lbs. of CYA took me to readings in excess of 110 PPM in approximately 11,000 gallons of water, nor can I explain why draining 2/3 of the pool water (the following year) and refilling with fresh water took me to 100 ppm. But that pool and all its water and problems are long gone, so it will remain a mystery.
No mystery at all. I have seen it many times. When CYA levels are very hiigh for an extended period of time CYA tends to deposit in the plumbimg and pool surfaces and when you refill it residdolves and brings the level higher than you expect. As far as the pool store folk not knowing why the water was making burning eyes...well, since I used to work in a pool store I don't have a lot of respect for a lot of people that work in them, 'nuff said?

Yes I am a slow learner, I don't just go out and buy or do everything everyone tells me to until I investigate it. After all when your own children and grandchildren tell you that their eyes burn in your pool, I will err on the the side of caution.
But how do you know which way to err? Less is not always best (as the best guess chart shows with chlorine levels!)
Hypothetical point, If there were burning eyes and the pool store said that everything was fine (because their testing method bleached out at high chlorine levels and could not detect the combined chlorine in the water--actually, I have seen this happen--and someone else said to add more chloirne to get rid of the burning eyes but your chlorine was already high (and your CYA was high). would you give it a try to see if it worked? I believe you know enough about pool chemistry now to know it would!

As far as the test kit is concerned, my old one was barely adequate, but wouldn't test CYA, so yes, I ordered the Taylor.

Have you received the Taylor kit yet? I think you will find there is a BIG difference between 'barely adequate' and a good test kit. If I remember right your old test kit was OTO and not DPD. There is a reason that the Taylor kit is recommended, otherwise we would probably recommend getting a cheap '5-way' kit from Ace Hardware and adding a CYA test to it. The end result is so different it is a case of apples and oranges!

[BigTallGuy]

Have you received the Taylor kit yet? I think you will find there is a BIG difference between 'barely adequate' and a good test kit. If I remember right your old test kit was OTO and not DPD. There is a reason that the Taylor kit is recommended, otherwise we would probably recommend getting a cheap '5-way' kit from Ace Hardware and adding a CYA test to it. The end result is so different it is a case of apples and oranges!

Not yet. I am expecting it this week. I am looking forward to working with this kit when it arrives.

Yes, barely adequate vs. good, I'm sure is miles apart. But for the record, since May, 2010, when I converted to Salt along with a new liner and fresh water, My pool has been sparkling clean, without a single algae bloom or "green" day, and no burning eyes (thanks to many people on this Forum) I only have had to add bleach one time. All with my old test kit and a few tests at the pool store. So justifying the $57 for a Taylor kit was a little rough. My last bout with the CYA levels (different Thread) was the last straw.

The residual CYA in the liner, plumbing etc. was suggested before and is the only thing that makes sense, as it would be chemically impossible to repeat the readings with 4 Lbs. of CYA. I didn't know until now if this was a real possibility or a theory. Thanks for clearing that up.

[BigTallGuy]

Thanks to all that responded. Famousdavis, I sincerely apologise for trashing your thread.

[waterbear]

"You're starting to believe, but I don't think you're quite there yet."

You're right. The proof (for me) will be how this forum's methodology holds up in *my* pool, right? But everyone here has convinced me that I don't have to blindly and ignorantly follow a local pool store's advice on how to care for my pool (for which I heartily thank you!). Moreover, you've raised an interesting, viable alternative that I'm willing to try -- keep up my CYA level, keep up my FC level, watch over my CC level, and shock only when the pool needs to be shocked. Doesn't have to be once a week. Doesn't have to be once a month, even. Just when I need it.

You have just stumbled on to the secret on how commercial pools are maintained!

So, I'll give it a go. My "insurance policy" against algae, though, is that I'll still add a maintenance dose of polyquat each week. The relatively low cost of doing that gives me peace-of-mind. What I need to work out now is how much time the SWCG needs to operate to keep up the FC level. Over this week and next, I should be able to nail that answer down.

Adding borates to 50 ppm is a better insurance policy, only has to be done once and you don't need to worry about it until the level drops to 30 ppm (for most people this is once a year), and they also help keep the pH from rising as fast so your pH becomes even more stable.

[famousdavis]

Supermom said, "Just an FYI (and somebody may have already told you this earlier in this thread -- I didn't take the time to re-read it) -------- polyquat will cause your FC to plummet. Then you'll have to add more chlorine to pull it back up."

I had a dip in my FC after doing a maintenance dose of polyquat, but it didn't plummet:

FC on Tuesday morning (which followed a SWCG shock on Sunday-to-Monday): 7 PPM
FC this Wednesday morning (polyquat in the water 24 hrs): 5 PPM

And the drop may not be entirely the polyquat. I'm trying to figure out how long I need to run the SWCG, and I think it's set right now so I l lose a little FC each day (0.5 to 1 PPM).

Waterbear: I dumped 3.5lbs of stabilizer in the skimmer this evening after getting a 55 PPM reading from my CYA test. Great tip you gave on re-testing the CYA using the same water, btw. I tried three times just to make sure I got repeatable results (I did). I think my problem with my earlier CYA testing -- where I kept still seeing a little bit of the black dot, even after I added all 14ml into the tube -- was because I didn't wait long enough before pouring in the mixture. Taylor's instructions say wait at least 30 seconds, but waiting a couple of minutes is much better. Anyway, I'll take a reading tomorrow and see if my CYA level is up around 80 PPM. Then I'll continue leaving my SWCG settings alone (50% for 8 hours) and see what happens to my FC levels. Thanks so much for providing some clear advice on chemical levels!