First time TF-100 testing.


New member
Aug 25, 2018
Hamlin, NY
I bought the TF-100 test kit after joining the group and did the first full test today. My quick daily test for Co/Br came up red not even on the scale of colors. My results for the full test were FC 24.5 with CC being 0 making TC 24.5. I only use the 3" chlorine pucks as of now and have them floating in a disperser wide open. My pH was 7.2, and my TA was 120. When I did my CYA test I was half way to the 100 line on the tube when I couldn't see the black dot anymore and there was no number line so its above 100. I didn't do a CH test as I don't think it applies to my pool. My water is clear with some algae starting to grow. I'm curious as to what I should start to do or need to do in order to close it up this year? I am going to leave it uncovered after a few failed attempts at keeping it on and one complete pool loss due to displacement and collapse. I want to try the slam method in the spring when opening. The pump currently is operating on a timer 10 hours a day from 9 am to 7pm EST.


Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
Laughlin, NV
Welcome to the forum! :handshake:

Your CYA test implies your CYA is way over 100 from the steady diet of solid chlorine. It would be advisable to get that in line plus SLAM Process the pool prior to closing. Or plan a very significant clean up and water exchange in the spring.

To test your CYA above 100, use Step 8 in Pool School - CYA

CH should still be monitored in a vinyl pool. Low CH can cause foaming and may be damaging to certain vinyls. High CH can create scale, even in a vinyl liner pool.

I suggest you read Pool School - ABCs of Pool Water Chemistry and consider reviewing the entire Trouble Free Pool School book.

You may also want to get the Pool Math app.


TFP Expert
LifeTime Supporter
Jan 6, 2010
San Dimas, CA (LA County)
The OTO colormatching test goes through intensities of yellow into orange and eventually brown. As high as your FC is, it is no wonder you couldn't find a match. Don't rely on that test anyway-- use the powder and drops. If the color test was good enough, the powder wouldn't have been included. The OTO is only included because it comes with the pH test.

Marty has covered the rest I was going to say. Check your CYA using dilution and yes, CH can matter.