Slam process for visible algae

[pkroll270]

I’ve been reading the forum for the past year. New pool owner and still learning. I’m following slam process for visible algae on the bottom of my pool. My chlorine dropped to zero during the day, so I started slam process. I used pool math to determine the amount of chlorine I need to add. I’m using 10% liquid bleach. I added 4 gallons and 1 quart to bring my FC to 16. 1 hour to 1 1/2 hours later, I took my FC test (FAS-DPD) using my TF 100 test kit. My FC showed 27.5. maybe I need to remeasure my gallons? What might be going on here? What would my FC be off so much?

FC- 27.5
CC- 1.5
PH-7.2
CYA-40
TA-80
CH-325

In addition, after my CC test, after I recorded my CC result. I left the test out, and the color changed back to pink before I had a chance to empty it. Is that normal?

Inground Fiberglass Diving Pool
26,000 gallons
Hayward sand Filter
Rectangular Shape
Thanks so much. Really enjoy this forum.

 

[mknauss]

Welcome to the forum!
Pool volume is normally the most likely cause of variance. How did you measure the volume of the pool?

I suggest you read ABC's of Pool Water Chemistry and consider reviewing the entire Pool School eBook.

 

[Richard320]

Welcome!

Pure speculation here... poolmath may have repopulated an entry somewhere with a default. Maybe it gave the dose for 6% bleach but you're using 10%?

 

[pkroll270]

Per

Welcome!

Pure speculation here... poolmath may have repopulated an entry somewhere with a default. Maybe it gave the dose for 6% bleach but you're using 10%?
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[pkroll270]

Thank you both. I will first remeasure my pool. Maybe I wasn’t accurate. I have been reading all the pool school articles. THis is what got me along so far. I’ve already learned so much. My pool hadn’t been maintained in several years when I opened that disaster last year. So, I rely on all the pool school articles and instructions. Thanks for the help! If my measurements are accurate, then I will look into my defaults.