Chlorine level - contradicting info on site

[graler]

I still consider myself a newbie at this pool care stuff. Have had the pool since last June - started out Baq then converted. I have done more than my fair share of testing. To start out my water is fabulous. I have some junk at the bottom (leaves and what appears to be dirt - puffs when brushed then settles back down). Here are the test results from this am.

FC 7.5
CC 0
TA 120
PH 7.5
CYA 35 ish < this remains to be the most difficult test to figure out.

Per Pool Math target FC is 3 to 7. I have always stayed in this range maybe even going up to 8 when I thought my CYA was around 50.

In the chart for non-SWG pools the ranges are
CYA 30 2 to 4
CYA 40 3 to 5
CYA 50 4 to 6
This chart does not agree with pool math or pool math doesn't match the chart.

I was aiming my bleach adds to push me up to 8. I am going to move that to 7 given the pool math recommended levels for 35 CYA.

An appropriate response to this might be - geez it looks great keep on doing what you are doing and swim for crying out loud.

 

[woodyp]

Go by the recommended numbers for your cya in the chart and just punch in what your now and target numbers should be or you want them to be and add accordingly.. I don't understand what you mean by NOT matching?

 

[kimkats]

And why are you NOT in the pool swimming??????? LOL

The only thing I would do is bump up your CYA due to being in hot Texas so that you hold onto more of your FC during the day. Yes the CYA test is a hard one to do but with practice and learning your pool you will find the sweet spot for your and your pool!

Your levels do look good so keep on doing what you are doing.

Kim

 

[Swampwoman]

Graylir, I suspect what you mean by the mismatch is that at 35 cya the pool Calc bumps you up 1 ppm on the min. as if you have 40 ppm cya and gives you a 1 ppm higher target fc range. I've noticed this as well

The chart is an approximation, simplified from a complex table. I believe the pool Calc is also based on the more complex table but accounts more closely for CYA increments as well as the need to dose to high end to maintain low end

So its not exactly a mismatch...just kinda like two economists interpreting a set of numbers...but way more accurate and fact-based

So ride high and go swim now

 

[pooldv]

The Chlorine CYA Chart wins. The most important thing is to never let your FC level drop below the minimum for your CYA or algae will be coming to your next pool party. Test later in the afternoon or early evening after the highest demand times and make sure it stays above the min.