Cya levels unexplainable high

[Jeff piper]

See attached for water chemistry .Water is 6 weeks old with spa marvel added along with borates in the rough area of 60ppm
.I used lithium hypochlorite in the beginning and switched to sodium hypochlorite 10.8 %about 2 weeks ago for sanitizer and used about 10 - 1 inch trichlor pucks in the floater during the 6 weeks. Questions
1) cya is greater than 169 if test is accurate, can I reduce it àny other way than drain and refill as it is -10*C in Ontario now.
2)can I burn off the combined chlorine or should I just leave it
3) under more normal senerio what conditions should a slam be considered and what would be the normal ppm to obtain.

Fc 4.95
Tc 8.37
Cc3.42
PH 8
Hardness 254
Adj Alk 44
Cya +169 ???? Could this be wrong?
temp 101*F
Tds 1600
Borate 60?

 

[needsajet]

Welcome to TFP! Good to have you here

Yes, members here have experienced incorrect results from pool $tores time and time and time again. You could try taking water to several pool $tores and observe the differences just for the giggles. If those were 14g (1/2 oz) tablets, you would have added about 65 ppm CYA. If they were 200g pucks, it would be over 900 ppm CYA

The only way to reduce CYA is to exchange water, probably two-thirds drain/refill would do the job if that number is correct.

You'll need to let the tub breathe to get rid of the combined chlorine.

pH at 8 could be the limit of the pool $tore's test, so I would get that down below 7.8 fairly quickly.

Here's an article on running a spa on chlorine: How do I use Chlorine in my Spa (or pool)?

There's way better experts here than me, so ask any questions that come up and people will be along to help.

 

[pooldv]

Welcome to T

+1 to all of that. I've been maintaining my tub with bleach and that process for many years and it works great. Leave the cover open for a bit, 30 min to an hour or so, to let the CC burn off. You also need to have sufficient FC level to burn off the CC. And retest FC in 30-60 min after a soak to make sure FC didn't drop to 0.

There is also good info in that article on lowering your TA to help slow PH rise.

 

[Jeff piper]

In your opinion ,do you think an slam of chlorine to 12ppm would do the trick?

 

[pooldv]

With CYA well over 100 all of the FC will be bound up by the CYA. You need to drain and refill to lower the CYA and then follow this, [FC/CYA][/FC/CYA]

 

[needsajet]

You need to pin down your CYA level before you'll be able to predict the outcome from adding chlorine. If your CYA is 169, then around 13 ppm FC is your bare minimum. So I'd say no, 12 ppm FC won't make any extraordinary difference.

If you're thinking about adopting trouble-free pool care, here's a link I learned from when I started out with TFPC. TFPC for Beginners

 

[tim5055]

Welcome to TFP!!

Not much credence is given to pool store testing around here. While you would think that a "professional" would be the best, unfortunately in most cases it is quite the opposite. Between employees who blindly trust the word of chemical sales representatives and high school kids working in the pool store for the summer you end up with poor results from their testing. But, what can you do?? We base our pool care system on accurate testing and only adding what the pool needs, when it needs it. To do that you need your own accurate test kit. Order a TF100 which will probably give you enough reagents for a couple/few of years normal use if you treat the kit well. Store it indoors in a cool dark place.

While you wait for it to get delivered, you have a homework reading assignment. Start with How do I use Chlorine in my Spa (or pool)?)