Questions on Readings (1st use of TF-100 kit)

tomliv

Member
Jun 7, 2020
6
MA
Hi,

In the past, I have been going to my local pool retailer and having them test my pool water. Last year, as a result of this site, I started using bleach/shock instead of the 3" stabilized chlorine pucks when I was battling high CYA.

This year, we needed to get the liner replaced, so new water was added to the pool. I did not have the test kit at the time, so I used the test information from the pool retailer with the goal of getting to minimum levels and fine tuning when the test kit arrived.

The test kit (TF-100) and the electronic stirrer (Smart Stir) arrived yesterday, and I took my first set of readings this morning:

FC 1.5
TC 1.5
pH 7.8
150-160 TA
20 CYA

For the TA test, the water started turning red at the 8th drop but then changed back. It took until 15-16 drops for the water to stay red. I took two readings as I did not expect it to be that high based on the amount of baking soda I had added to the pool at the beginning.

I know that I need to get the CYA up and will do so promptly. I can add some pH down that I have to drop the pH to the 7.5-7.6 range which I think will reduce the TA.

Anything I am missing or is of concern that I need to take care of? The water looks great.

Thanks in advance!
 
Last edited:

woodyp

Mod Squad
TFP Expert
LifeTime Supporter
Apr 17, 2010
10,949
East Texas
FC (free chlorine) +CC (combined chlorine) = TC (total chlorine). Did you actually test for CC or is that a misprint? Get your FC up to match your CYA requirements. Welcome to the forum.
 

tomliv

Member
Jun 7, 2020
6
MA
When I tested for combined chlorine, I added the 5 drops of R-0003 to the clear solution and swirled. It remained clear. So, I have no CC.
 

tomliv

Member
Jun 7, 2020
6
MA
Regarding the TA, I did wipe between each drop, but I don't think that I had the bottle vertically as I was afraid that the drops would just fall out by themselves. From what I have read here, the bottle needs to be vertical, otherwise I run the risk of smaller-size droplets and a reading higher than it actually is?

I checked the water at the pool store for a sanity check, and the TA reading there was 95. They use test strips but have a calibrated reader. I can't imagine that the pool store reading would be that far off (95 vs. 150-160), so I have to think that I messed up the test.
 

tomliv

Member
Jun 7, 2020
6
MA
My CYA is currently 30. I would like to keep it relatively low.

In Massachusetts, what should be a good target CYA? The pool sees sun from roughly 9 AM to 7 PM. I am replenishing 1-2 ppm per day (which I am fine with).