CYA Catastrophe

[annifred]

We recently installed a SWG after many years of using chlorine tablets (which I now see are rather disparagingly referred to as "pucks" here).

The chlorine and CYA are high. The pool school chart has shown me what a problem this actually is. I just ordered the TF 100 test kit.

Leslie's test results: FC and TC 10ppm, pH 7.6, TA 100, CYA 100 (I suspect it may be much higher), Salt 3700, CH 200

The Leslie's analysis report recommendation was to lower FC by adding Leslie's chlorine neutralizer and lower CYA with Leslie's Bio-Active CAR. The verbal recommendation was to turn off the SWG and it would drop naturally. And not to worry too much about CYA - it would eventually come down with backflushing dilution over time.

We turned off the SWG three weeks ago and the FC / TC is still 10 (aquacheck test strips, which I now know are a poor way to test).

OK, that was the background: my first question is what to tackle first? I think I should first address the CYA and keep an eye on FC and switch on the SWG when it drops, in the meantime not use the pool until we get chemistry sorted out and determine whether CC is a problem.

We live in CA, so the drought makes me tres reluctant to dump water to dilute. I can't find anything in past TFP posts about using Bio-Active, and the Leslie's chap said it was a pain to use and he didn't particularly recommend it. There are a few positive reviews from users on the Leslie's web page which may indicate that the negative reviewers didn't use it exactly as directed but it's hard to tell.

When the test kit arrives I will endeavor to get a better handle on the true CYA level (right now I think Leslie's result really means 100+ as it maxed out their test and they don't dilute the sample to verify the result). I would like to try the Bio Active to see if I can avoid draining the pool but would appreciate feedback about that idea. Thanks!

 

[gwegan]

Turn the swg on NOW. Your CYA is way to high. Even if it is 100 (and it is almost certainly higher your target is 12 and the minimum is 7.

Bio Active does not work for normal human beings.

The bad news is you are going to have to drain. I would drain and refill. That uses less water.

Welcome to TFP. Where Are you hidden up in those crazy hills?

 

[annifred]

Thanks, that was fast! OK, will do - the pool looks lovely and clear but from the urgency of your "NOW" direction I'm guessing that we are flirting with disaster

Yes, in the mountains but not too hidden!

 

[MarianParoo]

I hope your testkit arrives soon. It is really hard for us to make reccomendatiins based on pool store tests and strips.

You can also turn down the SWG and add a jug of bleach every day until your kit arrives.

 

[annifred]

I hope your testkit arrives soon. It is really hard for us to make reccomendatiins based on pool store tests and strips.

You can also turn down the SWG and add a jug of bleach every day until your kit arrives.

Righto, I will do that too. Thanks Marian! Will seek further input after doing proper testing.

Sent from my SM-G920V using Tapatalk

 

[lightingguy]

With a high CYA level the vast majority of the FC in the swimming pool is held in reserve (bound up in the CYA) - the amount of actual chlorine (hypochlorous acid) floating around in the pool is very low.

10ppm FC with no CYA in the water is too much chlorine indeed

10ppm FC with 100pm CYA in the the water isn't a big deal at all.

Until your test kit comes keep the chlorine level in the pool on the high side or you'll start to grow algae. I wouldn't bother with any sort of CYA remover yet. Better to get a sense of what the real numbers are and then form a plan.

The simplest solution will be to drain some portion of the water - but there are ways of managing high CYA for a period of time and then using rain water to dilute the pool. Either way - stop going to Leslies. Their advice will just have you going in circles.

 

[Isaac-1]

I am sorry to say, but it looks like bad advice from the free pool store water testing got you into this mess, and the bad advice the pool store is giving you now is just setting you are for more trouble. As the others have said, try to maintain Chlorine for now and we will have a better picture of your true situation once you get your own quality test kit in hand.

 

[max2k]

Righto, I will do that too. Thanks Marian! Will seek further input after doing proper testing.

Sent from my SM-G920V using Tapatalk

100 ppm CYA is manageable- I dropped mine down to 50 from 300 over 1.5 years by natural loss- back washing, emergency dumps during couple heavy rains, etc. I prob got 'lucky' as nearby rain drain got overflowed and dumped couple inches of rain water excess into the pool. All I had to do at the time is to pump my pool water out for the same amount and pray the lightning doesn't trip the power off.

During these 1.5 years we swam in the pool and it never got cloudy let alone green so you'll get there eventually. Please don't add anything but bleach to the water until you get your test kit.

 

[YippeeSkippy]

I just wonder if the Leslie's Freebie Pool Test actually maxed out at 10 (as we know many less accurate testers do) and the OP's FC may have even been higher at first?

Just as we know the CYA test only reads to 100, but with proper dilution and a little math one can get a proper reading.

 

[jeff1331]

Hey, you don't have an impending disaster here. I'm just hoping you weren't panicking from a few of the posts here. Relax, if you don't have algae, you're still fine. Lightingguy had the best advice, keep the chlorine on the high side while you deal with the CYA problem. The CYA isn't a thing that has to be solved immediately (like tomorrow). I once went a few months at close to 100.

He's right, get accurate CYA reading, then, devise your strategy for removing liquid water from the pool to drop it. It has to be liquid, not evaporation. You can drop the CYA over a period of time. I used mostly rain water to drop mine from 90 to 40. Took me about 3-4 months but I did it. I have an overflow drain so just made sure pool was full before rains and pump was running during all downpours. In the mean time, only use liquid chlorine to keep the levels high.

Essentially, stop using any chlorine with CYA added (pucks, dichlor, trichlor). If you have to shock, use calcium-based shock (calcium hypochlorate) unless you suspect your CH is too high, then just shock with liquid chlorine. BUT... unless you see algae, assume you don't need to shock. Hardly anybody needs to shock if you don't see algae. You can learn about conditions that would require shocking if you don't see algae later, that would be kind of rare anyway.

No woman, no cry. No algae, no worry. (Sing this to reggae). You can go with this until after you put down the pipe of ignorance but until then, no algae, no worries (and keep the chlorine high while you get a strategy down for reducing CYA).

 

[robertmee]

I just wonder if the Leslie's Freebie Pool Test actually maxed out at 10 (as we know many less accurate testers do) and the OP's FC may have even been higher at first?

Just as we know the CYA test only reads to 100, but with proper dilution and a little math one can get a proper reading.

I'm betting you're right as everyone seems to have glossed over the OP's note that they didn't lose FC from 10 in 3 weeks with the SWG turned off. That's not possible unless the pool was covered, or unless the OP failed to mention they were adding chlorine via other means. So, I don't think we know what the FC is right now, and therefore impossible to give any advice as to what to do right now with chlorine.

 

[pooldv]

That is correct. Many FC tests max at 10 and will read 10 even if it is 40. All CYA tests max out at 100.

Get an FAS/DPD chlorine test from TFTestkits.net, it can measure FC up to 50 ppm

Do the dilution test to read higher CYA levels.
Pool School - Extended Test Kit Directions

 

[annifred]

Thanks everyone for your advice - I went to bed with a guilty conscience last night (felt like I should be out there draining my pool and adding bleach and getting on with it). Today is a new day.

My test kit is on the way and should be here by the end of the week. Several people have pointed out that without doing a sample dilution it is not clear what the true FC level is and it must have been significantly higher since it is still maxing out the test strip indicator and we have added no chlorine for 3 weeks. I could try a 1:1 dilution and see what the test strips indicate but there's probably not much point now, it would have been more informative to have done that three weeks ago.

Anyhow, the consensus seems to be: add some bleach daily until the kit arrives and don't fret too much until I get some real numbers since the pool is still clear and happy looking. I will look at the pool math page tab to find out how much NaOCl solution to add for now.

What is the "OP" acronym? Never mind, just looked it up on Urban Dictionary - I was thinking it must be "Owner of Pool" but now I see it is "Original Poster". Ha! I need a pocket version of that dictionary!

 

[annifred]

I think the pool store guys are trying to be helpful (some of them anyway) - but without spending a ton of time going over the "big picture" with each customer they are giving best guess advice based on incomplete data. And of course they have a business to maintain and they are unlikely to be trained chemists. I take full responsibility for not understanding the complete picture going in and will attempt to be more discriminating in the advice I follow henceforth - this TFP community is going to be a fabulous resource, I wish I had done my homework sooner. I am very appreciative of all the help everyone has given already.

Case in point: the pool shop seemed horrified that our water tested at 2500 ppb for phosphates and recommended that we attack that problem first. I duly purchased their extra strength Phosfree product and we spent the first week of this odyssey going through the hoops needed to treat the pool with that stuff. I googled phosphates in pool water when I got home and there seems to be one school that believe phosphates are a fate worse than death, and another that think they are no big whoop if the rest of your chemistry is good and you don't have problems with algae. Then there is the orthophosphate / polyphosphate debate - ortho bad (fertilizers), poly no big deal (added by municipalities for management of pipe corrosion).

With some misgivings we went ahead and used the PhosFree anyway since we just paid $90 or so for it - our phosphates are now zero apparently on Leslie's retest, but our water company adds 2.8 ppm (ie. 2800 ppb) of polyphosphate so will have to come up with a plan for the future.

I see from reading past messages on these forums that we probably just wasted money, effort and time on this exercise. Again, my bad for not doing my homework before taking advice from the pool shop. Phosphate was going to be a future thread after I figure out my CYA strategy.

 

[max2k]

that future thread might not have much future - TFP openly doesn't care about phosphates. Up to the point that I still don't know level in my water after 1.5 years owning the pool. Your call of course but if I started to care I'd get my own reliable 'phosphates' test first as pool store might be inaccurate/biased. In any case TFP developed simple and affordable way to balance water which requires monitoring of 3 main parameters: FC, CYA & pH. The rest is 'fine tuning' and usually not time critical. I'm still puzzled what approach pool stores follow as I'm reading seemingly random recommendations based on unreliable data which looks more like snake oil than scientific. I don't even see how chemistry is relevant there.

 

[jeffchap]

I have not once measured phosphates in 6 years of pool ownership.

Nor have I ever had my water tested by anyone but myself.

 

[pooldv]

I have not once measured phosphates in 6 years of pool ownership.

Nor have I ever had my water tested by anyone but myself.

Ditto!

 

[borjis]

You might also look and see if you have Reverse Osmosis services in your area.

They could filter out the CYA, but it can be spendy. I've heard quotes from $ 400 - $ 600.

But it might be a viable option for you instead of water replacement.

 

[pooldv]

Keep in mind that RO also wastes 20-30% of the water.

 

[annifred]

that future thread might not have much future - TFP openly doesn't care about phosphates. Up to the point that I still don't know level in my water after 1.5 years owning the pool. Your call of course but if I started to care I'd get my own reliable 'phosphates' test first as pool store might be inaccurate/biased. In any case TFP developed simple and affordable way to balance water which requires monitoring of 3 main parameters: FC, CYA & pH. The rest is 'fine tuning' and usually not time critical. I'm still puzzled what approach pool stores follow as I'm reading seemingly random recommendations based on unreliable data which looks more like snake oil than scientific. I don't even see how chemistry is relevant there.

Yep, figured the past tense was going to stay that way for my phosphates questions. From reading around here I have picked up that nobody cares, which makes it a bit sad that Leslie's is able to scare the jinkies out of people with their phosphate testing. I guess they have a product to sell so they are sticking with the debunked theory that phosphates are algae food.

Again, my bad for not doing my homework, consider me duly enlightened.