Slamming with low CYA

Aug 6, 2014
49
Pearland, TX
My current numbers are:

FC 4.8 (just add cal hypo to raise to a 14)
CC .4
pH 7.5
TA 190
CH 150
CYA ??0-15-30??

Back story - I've been using the TFP method since last summer, but as with a lot of newbies I met my pool go over the summer (I had a bad break and surgery that prevented me from doing much). Last year we were battling black algea and I don't think we ever fully got rid of it. We are working on opening the pool for the summer after a winter of neglect (I'll never do that again if I can help it!) from a complete swamp (literally had tadpoles by the hundreds). So we have been slamming for about 9 or so days. We are filtering almost constantly, vacuuming and backwashing, scrubbing, all of that. We actually have the pool looking pretty darn good now, but we arent done with the Slam yet. We are keeping FC high to kill off the lingering black algea.

My concern is about CYA. I cannot seem to get any CYA to show up in testing. My test liquid is fresh, I just bought it last week. I have added 2 gallons of "Natural Chemistry's Instant Pool Water Conditioner", one last week, and one this week. I still can't get any to show up. With the 2 gallons by cya should be nearing 30 ppm, but nothing shows.

I know that you lose cya from dilution (we have had a lot of rain) and from backwashing or wasting water, and we have certainly done some of that.

1) I am concerned about constantly adding it, I don't want to end up on the other side with too much and have to do a partial drain and refill.
2)I am also concerned about accurate FC & CC reading when I cant seem to get a handle on how much or if I have cya in the pool.

Any advice?
 
I too found my CYA to be low a few days ago following all the Texas rain. I recently used granule stabilizer (in a sock) to help boost by CYA - ideally to about 50. But I need to wait a few days to see the results since stabilizer usually takes some time to show-up (excluding liquid form). Other question ... you mention CYA being 0 ..15...30? What test kit are you using, and are those varied numbers listed that way because you aren't quite sure how to perform it consistently, or you just aren't sure? Just curious to see if you needed help or clarification on the process to test CYA. It's very important when SLAMming and referring to the CYA/Chlorine Chart.
 
You don't have to constantly add CYA. CYA doesn't go anywhere unless you replace water. There are rare occurences of CYA getting eaten by rare bacteria and converted into ammonia. Ammonia will take copious amounts of chlorine to oxidize.

You probably have some CYA and you probably lost a little CYA due to backwashing and if you had enough rain to overfill the pool.

It can take up to a week for CYA to register. The CYA test is subjective and sensitive. Make sure that you are doing the CYA test accurately (scroll down to the CYA section):
Extended Test Kit Directions

Even if you follow the directions to a "T" there is variation in the test. You might wait a few more days to see if the latest CYA addition will show up.
 
I too found my CYA to be low a few days ago following all the Texas rain. I recently used granule stabilizer (in a sock) to help boost by CYA - ideally to about 50. But I need to wait a few days to see the results since stabilizer usually takes some time to show-up (excluding liquid form). Other question ... you mention CYA being 0 ..15...30? What test kit are you using, and are those varied numbers listed that way because you aren't quite sure how to perform it consistently, or you just aren't sure? Just curious to see if you needed help or clarification on the process to test CYA. It's very important when SLAMming and referring to the CYA/Chlorine Chart.

I said the cya was 0,15,30?? because I really don't know what it is, I cant get it to show up at all during testing. I am using the Taylor test kit recommended by TFP, and I have been using it for about a year, so I am pretty familiar with testing. the According to what I have added in the last 2 weeks, it should be between 15-30, but according to my readings it is a 0. Since it is a liquid, I thought that is would show up in the test sooner than a week, but even so 1 week after I added the 1st gallon it was still showing 0. We have been running the pump almost continually (taking breaks during bad weather), and doing a lot of brushing, so it should be fairly mixed in there.

I am thinking for taking a sample to the pool store and see if they read any cya, maybe its my kit?
 
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