CYA confusion

ElkPool

LifeTime Supporter
Jun 2, 2010
104
Elkridge, MD
With the Leslie's K-2006 test kit (the same as the good Taylor one, I believe), my CYA tests at 100+. That black dot sure disappears quickly. I was told that for BBB I'd need to drain half of my water. However, my concerns are:

1. Cheapo PoolTime test strips put my CYA at about 50. The color is nowhere near the dark orange/purple of high levels.

2. I have no noticeable algae growth (what are other symptoms of too-high CYA?)

3. Probably most importantly, I have NO IDEA where all that CYA would have come from. My pool was opened for the first time about a month and a half ago. Since then, I've put one to one-and-a-half gallons of conditioner in there (I was shooting for 30-40 ppm in a 25,000 gallon pool), and I've had pucks floating around, and I shocked it bigtime (with PoolTime shock) twice. THAT's going to take me over 100 CYA? Really?

I've been trying to handle my chemistry as best I can...I just don't understand where all this CYA came from. When I opened my pool this year, it was the first time in years it'd been opened (the original owner passed away and the house had been on the market for two years)...and the CYA measured at a flat zero.

I'll drain some of the water if I really need to, but what if the tests are wrong somehow? And what if I don't see any down side to keeping the water the way it is?

I'm jut confused...any help will be really appreciated.
 

ElkPool

LifeTime Supporter
Jun 2, 2010
104
Elkridge, MD
Note: I have a bunch of pool chemicals that I bought before I decided to try BBB...if I can swing using those this season without draining, if that will work better than BBB, that's what I'll do this year.

What dangers are there in using a pool-chemical/BBB hybrid? I mean, I'm still keeping the chlorine and pH in line using bleach and borax...
 

loughps

Well-known member
Apr 26, 2009
221
Northeast Ohio
I'd trust the liquid CYA test over any strip any time. I don't know what's in the PoolTime shock. If it's dichlor, there's CYA in there, if it's Cal Hypo, there's not. I can't really say how you got over 100 (but some others on here might be able to do all the math), but if the dot test is showing 100+, I'd drain and get it down to 50 ppm if you plan on using liquid chlorine as your primary chlorine source.

If you decide to use the chemicals you have on hand, and assuming they're trichlor based pucks, you'll want your CYA down around 30 ppm now because trichlor will raise it over the season. You'll also likely end up needing to do another drain and refill late this season or when opening next season. I'd just store the other chemicals and use them as needed and switch to liquid chlorine, it's going to be cheaper in the long run.

Also, if you decide to use a "hybrid" method, a good test kit will be essential (really it's essential no matter what.) Keep an eye on all your levels and if using the leftover chemicals is getting things out of line, then stop using whatever is messing things up (usually it's going to be the trichlor that ends up causing problems with high CYA and low relative FC levels.)

Hope that helps. If you want to post all the chemicals that you have, I'm sure you'll get suggestion for the usefulness of each of them.
 

loughps

Well-known member
Apr 26, 2009
221
Northeast Ohio
I looked up the MSDS for the PoolTime shock products and saw that they're mainly dichlor. This is the most likely culprit for you high CYA. That plus the one-and-a-half gallons you added at the beginning of the season almost surely got you over 100 and the trichlor pucks just added to it.

If you still decide on the hybrid approach this year, I'd suggest liquid chlorine anytime you shock. This won't add any calcium or CYA as it raises your FC level. I still recommend draining to get your CYA under control as I said in my last post.
 

ElkPool

LifeTime Supporter
Jun 2, 2010
104
Elkridge, MD
Thanks for your advice. By "liquid chlorine", do you mean bleach, or something else? And how will I know when it's time to shock? My water is nice and clear now, no signs of algae...even though I bought a bunch of that PoolTime shock, I'd rather not use it (and will take your advice and use something different if I do in fact need to shock)

If it's this easy to take CYA up to unacceptable levels...wow. Those chemical companies should be ashamed of themselves. I really have tried to do everything right.
 

cheddar85

Well-known member
Feb 18, 2010
271
Houston, TX
Either bleach or liquid chlorine from the pool store will work. Same thing, just different concentrations. Try to find out what's cheaper per gallon, and use that one.
 

Bama Rambler

Mod Squad
TFP Expert
LifeTime Supporter
Jun 22, 2009
22,969
SouthWest Alabama
Just to give you some reinforcement that your over 100 test is correct. Adding 1½ gallons of conditioner to a 25000 gallon pool adds 58ppm CYA. Adding dichlor to that and using pucks floating around. Yeah, you'd be close to 100 by now. You'd definitely be way over 50!
 

loughps

Well-known member
Apr 26, 2009
221
Northeast Ohio
As to how will you know when it's time to shock, usually it's when you're having problems like cloudiness, or you KNOW something bad happened (like a little kids "floating" accident. :( ) You also want to shock if you CC level is ever more than .5 ppm. And if you just suspect things aren't right, you can do an overnight FC loss test. If you lose more than 1 ppm FC during the night while there is no sun on the pool, you need to shock.

With a nice clear pool, if all your numbers are in range and you keep your FC level in range for your CYA level, you might never need to shock.

You can also post a full set of numbers and ask questions on here, someone will help you figure out if shocking (even for a day or two) will help with whatever problem you're having.

If you can return the PoolTime shock, I would recommend that. That's the one thing you're going to have the least use for. If you can't, save it and if you ever need to add CYA to the water (which often happens in the spring) you can use the dichlor for part of that process, you just want to know what your adding. If you have the Shock XtraBlue, I don't recommend it at all because the MSDS lists copper which can cause problems (as well as two trade secret chemicals and one proprietary blend, I like to KNOW what I'm putting in my pool!!)
 

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