cya and other levels

[dalejanus]

I have 24 ft AG vinyl. I have been using BBB method for as long as I had my pool, 9 years.
Every year, we cover the pool and open it with no CYA, I have added 2 pounds using sock method. Yet when I test with Taylor k2006, the I can still see kinda the dot at 30 (full level).

Fc = 3
cC=0
PH= 7.2 to 7.4
ta=60
cya 30 or less

Should I add another pound and see if CYA goes up?

Also, should I try to raise alk? to 70 or 80?

thanks, this forum is a fantastic place to learn about pools and what is needed to maintain them.

The only time I go to the pool store is to buy stabilizer. I have to bite my tongue when I see people buying all those chemicals.

[AnnaK]

Two pounds of stabilizer in 12,000 gallons raise the CYA by about 20 ppm. You can add another 2 pounds.

My pool runs on 60 ppm TA because that's the level in my fill water. Since all values hold well and I have no pH fluctuations, I leave it alone. My pH stays at 7.5. If yours tends to drop then you could raise alk to 80 and see if that helps.

Thank you for filling out the Pool Chart! It makes it so much easier to respond to questions.

[dalejanus]

Two pounds of stabilizer in 12,000 gallons raise the CYA by about 20 ppm. You can add another 2 pounds.

My pool runs on 60 ppm TA because that's the level in my fill water. Since all values hold well and I have no pH fluctuations, I leave it alone. My pH stays at 7.5. If yours tends to drop then you could raise alk to 80 and see if that helps.

Thank you for filling out the Pool Chart! It makes it so much easier to respond to questions.

ok, I will get more stabilizer. I guess that means the test kit is reporting correctly.

My PH has always been pretty steady, 7.2 to 7.4, but in years past my alk was higher than 60.
We add about 1 foot of water each year, I guess around 4,000 gal. Maybe the city water dept changed their alk levels.

I have raised ph by aerating on occasion. As you say, since ph is holding steady, the alk probably doesn't matter.

I just discovered the pool chart. Great idea. This whole forum is a great idea. I just remember my first trip to the pool store years ago before I found this forum and getting a printout of all the $tuff I needed to buy and not understanding any of it.
thanks.

[AnnaK]

Testing for CYA is really very subjective. It depends on the lighting a lot. A good way to do it is to turn your back to the sun, hold the test tube at waist level, and look straight down. A freind of mine swears she can still see the dot when I read her CYA as 60 ppm, go figure. The good news is that none of these numbers are carved in stone. They come in ranges and adjust not only for testing variations but also volume variations. A slightly higher CYA, say 70 ppm, requires a little more chlorine. A slightly lower CYA, something around 30, means the sun will deplete your chlorine faster. Once you get a feel for your pool you can pretty much manage the fluctuations in your sleep.

I prefer to maintain pH at 7.5. Fortunately, that's what my pool wants to be at, so I rarely have to adjust it. Having it toward the high range, from 7.6 to 7.8, gives you the 'wiggle room' Watermom frequently mentions, especially if you use trichlor pucks in floaters now and then. I get a lot of aeration in my pool from the dogs diving in, and we, too, replace a lot of water that they drag out on their fur every time they exit.

A 24' round with a functional water depth of 4' holds about 13,500 gallons. Your guess of replacing about 4,000 each season is close enough. With that amount of water replacement you don't have to lose sleep if your CYA level gets a little high because you pretty much dilute it over time.

One thing I would suggest is that you test your fill water (except for CYA) and record that somewhere.