Really confused

[wprileyjr3]

I got a TF 100 kit so I have been using it. Saturday first test results were
FC 4.5 CC 0.5 PH 7.5 CH 325 TA 150 CYA 60. I added some water probably a couple inches in my 22000 gallon vinyl lined pool. Sunday FC 4 CC 0.5 PH 7.5
CH 300 TA 130 CYA 50. I added a gallon of concentrated chlorox to try to raise FC to 6 based on Chlorine to CYA chart. Tested today. FC 2 CC 0 PH 7.5 CH 250 TA 80 CYA 50. Not sure what happened it has been sunny and 90 all three days and all of a sudden chlorine is gone. I am a newbie so any advice would be appreciated.

 

[mknauss]

Welcome to the forum! :handshake:

Maintain your FC based on your CYA using the [FC/CYA][/FC/CYA].

Do not use Clorox brand as it has Cloromax addtives. Find plain bleach or liquid chlorine.

Your pool needs 2-4 ppm of FC added per day. You want your FC when you test to have the target level FC as shown in [FC/CYA][/FC/CYA] left in the pool. You then add enough LC to increase your FC enough to cover the loss over the next 24 hours.

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[wprileyjr3]

Thanks for the info. I didn’t have any liquid chlorine so last night I added 1.5 lbs of 73% calhypo to get FC up. According to pool math app should have taken FC to 8. After work tested the water.
Results were FC 4.5 CC 0.5 PH 7.5 CH 225 TA 90 Cya 50. So I am guessing FC loss of about 3.5. I went and got 10% liquid chlorine and added 3 quarts should get back to FC 8 will see tomorrow what it is. I am hoping after a few days I can get a good idea of how much to add each day without fas-dpd testing. I have trouble at these FC levels reading the comparator that came with my TF 100.

 

[mknauss]

Use the FAS-DPD test for FC. The OTO test (yellow color comparator) is rarely used.

Use a 10 ml sample, the powder and then reagent. Each drop equals 0.5ppm. Follow the directions that came with the kit.

With a CYA of 50 it is preferred if you have the minimum FC each day be in the target range, or 6-8 ppm. So you would add your daily loss to that number and that is what you add LC each day to reach. If your loss is 3.5ppm FC per day, I would suggest taking FC to 10 ppm when you add LC.