Slamming, huge loss of FC in short time

[milesvdustin]

Hey all! We recently had a lot of rain over two weeks, and i got a bit of cloudy water and i think some algae. I started a SLAM on Sunday. Cya is at 40.

I am keeping the fc at 16 per the chart. Vinyl aboveground, sand filter. I checked it last night and somehow the fc was at 21.5. I checked in the morning and it was 20. It did have some sun exposure so i think i only lost 1 ppm last night. Cc are .5 or less, water is clear. I have scrubbed skimmer, ladder, brushed twice a day during the slam and vac to waste anything on the bottom.

So here is my problem: I had my wife check the water 6 hours after I did, and the FC dropped to 8? Whats going on?

Full numbers as of right now

Fc 8
Cc .5
Cya 40
Ta 110
Ch 220
Ph 7.6 (i think, fc is a little high for accuracy.)

Using a tf100 test kit i got here last summer.

 

[cj3737]

Sun will burn off some of the chlorine and the algae will consume the rest...Maybe a slight difference in testing methods...
Keep it at 16 until you pass oclt and the water is clear again...

 

[milesvdustin]

I think my wifes methid of testing is way off. That wouod explain why jt was at 20 when i had her add chlorine to get fc to 16, but way overshot.

It was 20 when i went to work, and 10.5 when i got home.

 

[cj3737]

You've definitely got some algae.. I think normal sun burn off, even in Texas sun, is less than 4 so you've got some growers in there...Keep slamming until your FC starts to level off a bit more.

Over shooting right now isn't a terrible thing I think when I started my slam I targeted 16 but shot up to 22 the first little bit... Itll burn off and consume the algae so no worries.. Just "try" to keep it near 16

 

[milesvdustin]

It passed the oclt last night. I am continuing the slam til the weekend to be sure. Water is crystal clear. No cc.

 

[milesvdustin]

looking good!