CYA will not budge (upward)

[PhillipH]

Regardless of how much CYA I add, I simply cannot get the CYA level to move up. It's been at 40-50 for weeks, despite me adding alot of CYA. I always add it slowly, and I've added most of it through a sock in the skimmer. Typically 1 lb, dissolve, then 2 lbs, dissolve, etc. I don't know how I could be doing it wrong, but I also have no idea how the CYA level hasn't increased. I've added about 10 lbs of granular CYA since early May.

For all of the test results, I've been using the TF-100 test kit.

I know everyone's opinion of pool store employees, but coincidentally, the pool store guy told me before all of this happened that I could add all of the CYA I wanted and still might not get it to 80. I still want my level to be 70-80 based on TFP targets.

Anyone seen anything like this before?

Here are my log entries from the last couple of months.

Date Tested-by FC TC pH Ca TA CYA Salt Temp CSI LSI

[attachment=0:h3iv96q8]pool_log.jpg[/attachment:h3iv96q8]

Thanks.

 

[JasonLion]

What are you using to measure your CYA level? Test strips and pool stores can both be wildly inaccurate.

Another thing that can keep the CYA level down is if you have a leak and an autofill system. That can result in a lot of water replacement, without being really obvious about it.

 

[duraleigh]

Hi, Phillip,

Let's confirm that you don't use an autofill and that you are replacing water (refilling) at what you consider a normal rate. That's about the only way CYA can leave a pool. While you're confirming that, I gonna' look carefully again at that chart (very organized, btw :lol: ) but what you are deascribing is virtually impossible if you don't have a leak.

 

[PhillipH]

Thanks for the help. No autofill system. I just use the hose to add water occasionally when necessary. I've had to do that maybe 3 times this season as the water gets to the bottom of the skimmer window. I'll add 3-5" to get it back up to the middle of the skimmer window.

I'm using the CYA test in the TF-100 kit. When I order refills soon, I was thinking about buying the standard CYA vial to do a sanity check. My fear is that the CYA is actually going way up, but I'm somehow measuring incorrectly (my FC is still maintaining well enough with consistent cell % setting). It's crazy that I measure 45-50 every single time despite the amt of CYA I've added. The funny thing is that I feel quite confident with the CYA "opacity" test (or whatever it's called). I'll always repeat the test, and I always get the same result twice in a row. Maybe I'm doing something wrong, but I've talked to you guys and I've seen the pics from Taylor on when to "call it". Regardless, the measured value hasn't moved while I've added 10 lbs of CYA over the last 2 months.

Note that the table entries that show "Tested-by = BD" are the pool store, Blue Dolphin. Back in April, they measured CYA=30, then on 5/19 they measured CYA=60.

Thanks.

 

[duraleigh]

reviewing your table, it looks like you added 9lbs of CYA since 5/1. That will increase your pool by roughly 40ppm.

Do you have reason to believe the 30ppm CYA test prior to 5/1? If so, your CYA is now 70ppm. Sometimes the math is more accurate than the test.

 

[shacke]

I am having the same issue.

I had my CYA level at 40. I added 2 gallons of liquid stabilizer and it is only 50 now. I added another gallon today and it is still 50. No autofill and fill only with the hot weather from evaporation to keep the skimmers happy.

I am testing with the TF100 kit also and at first I thought it was off after adding 2 gals (which should raise my pool 32ppm) but Leslies got the same result.

Do these levels creep up over time - even with the instant CYA in liquid form?

I am also concerned about adding toooo much.

Thank you.

Evan

 

[Isaac-1]

I seem to remember someone posting a message about bad /defective stabilizer being on the market a couple of years ago, have you used the same source/type/brand for all the stabilizer you have added?

Ike

 

[shacke]

Yes - same brand that Leslie's sells. They got me from 0 to 40 lickety split but it hasn't really budged since with another 3 gallons of the stuff. I am going to switch to the powder - the cost is a bit outrageous at this point and I may have better luck although I am not sure where it is going. In case it is clumping in the filter from not being totally in solution I will keep an eye on this latest gallon and retest in a week.

 

[PhillipH]

It's 10 lbs if you look carefully at my notes. The first 8 lbs was in the form of two 4-lb granular bottles from Blue Dolphin. After those didn't do anything and Jason mentioned something about a benign batch of CYA, I bought the third 4-lb granular bottle from The Pool Store. I've added 2 lbs from that bottle so far. Still sitting at ~50ppm according to my TF-100 test.

The 30ppm result was from sometime in April, and it was from the Blue Dolphin pool store test. My water was much cooler, so it could have affected that result. I take all pool store test results with a grain of salt. Having said that, Blue Dolphin at least used drop testing and not strip testing.

 

[PhillipH]

I guess I've stumped the experts?? LOL. Well, I have to admit that this one is pretty hard to explain -- other than the pool store guy telling me that CYA can be very hard to get up to higher levels. No idea why that is and I've never come across anything else saying that, but it's the only thing that's making sense right now.

 

[Bama Rambler]

According to the Pool Calc 10 lbs would have brought you to 48ppm. You say you're reading 50ppm so I'd say that's pretty close to what you should be reading.

 

[Mona]

According to the Pool Calc 10 lbs would have brought you to 48ppm. You say you're reading 50ppm so I'd say that's pretty close to what you should be reading.

He started with 30ppm already, then add the 48, so should be at 78ppm.

 

[Bama Rambler]

Yeah but that 30 was from the pool store and they are notoriously bad at measuring CYA. So he could have really started at zero. I've had two different pool stores tell me that I had CYA in tap water.

Phillip -- One thing I would suggest you do is order some CYA standard from TFtestkits and check your testing method. That way you'll be ruling out a testing error.

 

[Melt In The Sun]

He started with 30ppm already, then add the 48, so should be at 78ppm.

That 30 ppm being from the pool store, I wouldn't trust it.

the pool store guy telling me that CYA can be very hard to get up to higher levels. No idea why that is and I've never come across anything else saying that, but it's the only thing that's making sense right now.

That's just untrue. If you put CYA in your water, it stays there unless it's being leaked or backwashed out (neither of which is happening in your case). I agree w/ Bama; I think you started near zero and have added about 50 ppm, and your test is accurate.

 

[PhillipH]

I didn't start near 0. The PS reported around 30, but my TF-100 has shown my level to be 40-50ppm the entire time I've been adding the 10 lbs of CYA. It's almost like I'm testing the CYA standard! LOL.

Yeah, I definitely plan to buy some of the standard and check my testing. I assume you can dilute the standard to test out another ppm level? I think I read that the standard is 50ppm, but that's not the best number for me since that's what I always get anyway. Can I dilute by 1/2 and expect to read 25ppm? I don't guess there's any way to double the concentration and expect a result of 100ppm?

Thanks.

 

[Melt In The Sun]

Yep, diluting with tap water 1:1 would give you a reading of 25. There isn't an easy way to double the concentration though.

 

[shacke]

While it says 'instant' on the bottle, the liquid conditioner is not instant. After about a week, my CYA is now about 70. Good thing to know.

 

[PhillipH]

Here's a follow-up FYI.

I got the CYA standard from TF Testkits. Tested dead-on 50ppm. I assume you are supposed to treat the standard as the pool water when performing the test procedure? In other words, fill the CYA test vial to the bottom of the label with the standard, then fill to the top of the label with R-0013? That's what I did, and I got exactly 50ppm. Tested my pool water after that and got 45ppm yet again. That's what I've been getting all summer despite adding 10 lbs of CYA (2.5 bottles from 2 different pool stores). I added 2 more lbs yesterday after the test, so I'll give that a few days and retest. My pool is currently 93 degrees, and the CYA dissolved super fast in the sock in the skimmer.

I just find it so hard to believe that my CYA won't increase. The only thing I've heard to defend this is the pool store guy telling me that it can be nearly impossible to get CYA to the 70-80 range. I don't understand that.

Phillip

 

[Shane1]

I read a post from chem geek that certain bacteria can convert CYA into ammonia, but the pool has to be pretty bad off for that to happen. Just a thought.

 

[anonapersona]

I just find it so hard to believe that my CYA won't increase. The only thing I've heard to defend this is the pool store guy telling me that it can be nearly impossible to get CYA to the 70-80 range. I don't understand that.
Phillip

Well I certainly have had CYA above 150 so that is nonsense.