Did I mess up - CYA

[Pepperdinegal]

I’ve been trying to fine tune my chems and I think I might’ve made a mistake. My CYA was reading as 40 and using pool math, it said to add 8lb of dry stabilizer to bring it up to 70 bc I’m running a SWG. Yesterday I added it in women’s knee socks in front of 4 of the returns. I went out every hour for about 6 hours to squeeze and brush. Today I measured the CYA and it’s showing 80 (bordering on 90). Could I be getting a false high reading because it’s not thoroughly mixed in? Or will it go even higher? If it truly is that high, did I screw myself? Here are the rest of my readings:

FC : 10
pH : 7.4 (trying to bring the TA down)
CYA : 80 (maybe closer to 90)
TA : 130

Do I need to drain some of the water? It’s Vegas, so the outside temp will be over 100 for the next month. Will that help burn off some of the CYA? As long as I keep my FC up above 8 will I be okay for the kids playing in the pool?

 

[mgtfp]

Just make sure to keep your FC high enough for CYA 90 (you say closer to 90, so go with 90). CYA 90 should not be a problem with a SWG, might even turn out to be great in your climate. As long as you don't let algae get a hold, you should be fine.

 

[Pepperdinegal]

Is the only real downside to higher CYA in regards to the difficulty to SLAM if necessary?

 

[mgtfp]

Just stay vigilant in avoiding a SLAM. I always keep FC in summer around 80, sometimes 90, never had a problem.

We recommend CYA up to 90 with SWGs because there a great FC saving effects, and because of the reliable chlorine generation with a SWG it is easy to avoid having to SLAM, therefore the benefit to risk ratio is right with a SWG.

And remember, that any FC up to SLAM FC for your CYA is safe to swim in.

There would be nothing wrong in keeping FC at the upper target range (which would be 12), or even a bit higher.

Only disadvantage of keeping FC above 10 is the interference with the pH test. Even that can be worked around by using the distilled water method described here:

PH - Further Reading

www.troublefreepool.com

 

[mgtfp]

Is the only real downside to higher CYA in regards to the difficulty to SLAM if necessary?

Short answer yes. I was already typing my long answer while your follow up came in.

 

[an1vrsy]

There are times when my CYA degrades down to 60. I'll add to get to CYA 70 and sometimes I overshoot at bit. Since TFP always rounds up, I treat it as CYA 80. It doesn't really matter in that I always hover around FC 10 or so. Your CYA 90 will degrade, however, keep an eye on running FC hot until it does.