CYA Gone!

[Propbndr]

Got back Sunday from a long weekend to a cloudy green pool. Tested FC, was 0. It had been running 5-6. Using my last cya I added enough 6.5 jugs of 8.25% bleach. That should have brought it up to an FC of 31 but, another test 30 minutes later showed a level of 1. Added my last 2 jugs, put my swg on super chlorinate and went to bed. Tested this morning and found a FC level of 1 and a CC of 4. Out of bleach so added a pound of shock I keep on hand to sterilize my travel trailer potable water system. Today bought more shock and bleach. Came home this evening and found a clear pool but a bunch of dead alge on the bottom. Tested FC this evening, it was 0 again.

I tested my cya level and also found it to be 0. Last tested my cya level on June 16, it was a solid 80. What happened to it? There has been no bad rains in my area and a salt level test is the same now as it was on June 16th, a solid 3400, so dilution is not the reason.

 

[pooldv]

In rare instances with low to no FC in the pool bacteria can consume CYA in a nitrification process. Raise FC to 10 ppm and test in 15 minutes. If it stays at 5 or higher then add CYA to the pool and SLAM Process. If it drops to 0 raise it to 10 again and test in 15 minutes until it holds.

 

[Propbndr]

I guess between the shock and all the bleach I added over the past 2 days killed whatever was eating the cya. The 15 minute test after adding 2 jugs of bleach was 9.5. Started adding stabilizer and keeping fingers crossed this will be a short cleanup.

 

[pooldv]

Alright! Good plan!

 

[MarianParoo]

That was lucky!!!! Here's to a quick SLAM.

 

[Propbndr]

I may have dodged a bullet. Stabilizer level up to normal levels, thank god for quick dissolving stuff. 0 chlorine loss last night. Will test again to be sure.

Levels as of this evening
FC 7.5
Cc 0
Ph 6.8
TA 70
Ch 100
Cya 80

Keeping fingers crossed for a good OCLT test tomorrow morning. Need to add ph up to get it back to normal. Aeration will take forever.

The water is actually crystal clear, just a bunch of dead alge on the bottom. Brushed it to the floor drains instead of vacuuming it to waste. I need to add water before I can do that and I don't want to screw things up until I know my levels are steady.

 

[MarianParoo]

Do you have pH up on hand? If not, buy 20 Mule Team Borax instead.

 

[Propbndr]

Oh well. OCLT showed a 3.5 drop. Gotta continue SLAM.

 

[Propbndr]

Question.....why would I have 2 OCLT tests with a drop of 4 but a 0 CC reading each time? If something is "eating" my chlorine wouldn't it show up in a rise in CC?

 

[pooldv]

CC is fleeting and timing is everything to catch it. That is why it is only one of three criteria. I had some algae last summer and had 0 CC during the whole SLAM. Higher FC also helps to burn off CC quicker as it is produced.