10 ml test with R-0870 won't turn pink

[Chaddyp59]

I tested yesterday morning and had 2.5 FC. I added 121 oz of 8.25 clorox to bump it up to 7 or a touch above. We lounged in the pool yesterday and I went to test this morning and the sample won't turn pink. No way I lost all fc one day. I added small amounts of acid over the past couple days to lower TA and was about to aerate to bump PH back up. Now this??? Water is clear and beautiful, fresh off of partial drain and refill to lower cya..

The end of the tester spoon is black, but the powder inside is dry. Is there any way this suff goes bad overnight?

Fc ???
TA 140
Ph 7.2
Cya 30

Brandon, MS
20000 gallon in ground vinyl
sand filter
hayward super 2 - 1 hp pump

 

[karmabiker]

Doubtful. Try putting a drop or 2 of CL into the sample then add 870 and see if it turns pink. You could be at CL 0.

 

[jblizzle]

Do you have the yellow color matching OTO test? It is not in the K2006. That would tell you definitively if the FC was 0.

 

[Chaddyp59]

I do not have the OTO test. Just what came in the K2006. I don't think I could be at 0 on chlorine after just one day with no algae when it has been tested daily and doing fine for the past 3 days.

 

[jblizzle]

Well, there is really no other explanation as to why the FAS-DPD did not turn pink. With 10ml water sample and FC expected to be <10ppm a single scoop of powder should be plenty to turn it pink if there was any chlorine in the water.

Adding a drop of bleach to the sample would make the FC level way too high I think.

 

[Chaddyp59]

I just read about Ascorbic acid eating chlorine. I did use two bottles of vitamin C tablets in a sock to clean steps yesterday morning. Do you think that little of Vitamin C tablets would zap chlorine down?

 

[jblizzle]

Certainly would be a contributing factor.

 

[Chaddyp59]

Well I adding 121 oz of 8.25% before I left for work this morning. I will add a couple drops of it in test and see if it turns pink this afternoon, before I test pool water again.

 

[jblizzle]

Don't add drops of bleach in your test. 1 drop in 10 ml of pool water would be the equivalent of adding 1 gallon to 200 gallons of water ... which would make the FC level in your test 424ppm. The sample would not turn pink, it would bleach out.

Just test the pool. Really you should have added the bottle of bleach and tested the pool after 30 minutes to verify the FC level.

 

[Bama Rambler]

That vitamin C definitely neutralized all your FC. It may take several bottles of bleach to get the FC back, AND since it's been zero for a while you probably need to SLAM. It would probably be a good idea to just in case.

 

[Chaddyp59]

I came home and tested yesterday afternoon around 5:30 pm after putting 121oz of 8.25% in yesterday morning. Still wouldn't turn pink. I added 242oz and tested an hr later. It read 11ppm on this test so I felt better. Tested this morning at 6:30am and still reading 11ppm. I am going to test again this afternoon when I get home.

Brandon, MS
20000 gallon in ground vinyl
sand filter
hayward super 2 - 1 hp pump