Seanhan said:
I just got my tf-100 today !!!
30,000 gallon gunite pool that has been glassed by fibertech.
Swg
72 sq ft de filter
2hp pump
Ph = 7.5
Cya = 110
Free clorine= 10
Cc= .5
Tc=10.5
Ta=200
Calcium=200
Salt = 3800
Clorine 5+
My ta is too high should i add acid ??? How much ???
First, a tip: when you do the FAS-DPD (powder) test for Chlorine, you don't need to do the color matching test. Unless you want to see how good you are at guessing FC based on subtle shades of color. I discovered anything between 4 and 7 looks like 5 to me. But before I get carried away....
Your CYA is too high. If you think it's 110, it's probably closer to 150. The scale is loagrithmic - you might notice that as the numbers increase, the spacing gets smaller. The way to get a better idea of CYA is to use one of the cylinders to mix half pool water and half tap water, then pour that diluted sample into the mixing bottle with the R-0013. Take a reading, pour it back in the mixing bottle, repeat several times until you're pretty sure of yourself. Then double that reading.
High CYA in itself is not a huge problem, but if you develop algae, it will be. In that case you will need to use barrels full of bleach to wipe it out. Also, you won't use more chlorine, but you'll need to maintain much higher levels for it to be effective, which means you'll need to use the FAS-DPD test every time. I managed with higher CYA my first season due to water restrictions, so I know it can be done. But I don't recommend it. So consider draining and refilling some of it.
TA will come down by itself if you maintain pH. If you want to speed the process,
here's how. Note: you'll end up using the same amount of acid to do it, it just speeds it up.