Yo-Yo ing FC level

Jsloan1109 · Apr 15, 2015

Need a quick check in folks. I did the TFP method last year with great success and beautiful pool water. Just opened my pool this year.

My CYA is not registering. I am assuming my CYA is in the 0-20 range after the winter and I realize I need to add CYA. I live out in the middle of NM and there is no liquid CYA within a reasonable drive. I have some being delivered tomorrow. I really want to use the liquid so I can check the CYA immediately and get it under control quickly rather than use powder and wait a week.

My FC read zero this AM. I mean I couldn't get pink to show up at all. My issue is after not being able to get a reading on the FC this AM (I repeated the test to make sure). I put in bleach to take it from 0 to 3 (approx. 130 oz of 8.25 bleach using the calculator). Went out about 4 hours later and retested FC. My FC is up over at 13 (I repeated twice)! What is going on?

Is this total operator error? Water temp was over 70 this AM and filter had been off overnight. Did I mess up by not letting the filter run a bit and the water warm up to closer to 80? Kids want to swim this afternoon and now I fear letting them in. Solar cover is off now so sun should be eating up the chlorine.

Patrick_B · Apr 15, 2015

Ok, not sure where but there is a mistake somewhere. That should not get you to 13-14 FC in 25,000 gallons. If you are sure of the number ( I assume you're right) then wait it out. Sorry kids, no swimming till FC comes down to 3.0. Not with zero or near it CYA. 3 is the limit there.

Perhaps the error was your entry into pool math, but just can't say.

Kiss4aFrog · Apr 15, 2015

Well . . . I can't figure out what happened as the math just doesn't make sense. Zero FC, 130 oz into 25K you should have had 3-4 FC ?? Four hours later you somehow have 4X more.
Were you running the pump for that 4 hrs ??

jblizzle · Apr 15, 2015

To be clear ... what test kit are you using?

Jsloan1109 · Apr 15, 2015

Yes, I ran the pump and I am using a Taylor K-2006

tim5055 · Apr 15, 2015

Even liquid CYA does not register immediately. Folks report it taking days to a week for it also.

Patrick_B · Apr 15, 2015

I saw your old posts so I assumed you ran the right test. So, it's sunny today and that should get your FC down by tonight. How far, can't say but it should be a good deal. You have CYA coming so that's good. Recheck FC whenever this evening and see how it does. Try to figure out where the error was but don't sweat it. We all make a mistake sometime.

Did you use a 10ml test on the FC? Sometimes we have this a a reason for error. Wrong multiplier versus sample size that is. Just trying to cover the basics first.