My pool was installed in Q1 and started using it in March. I’ve been using a pool guy to stay on top the chemicals and been cleaning it myself. For a number of weeks I’ve been getting mustard Algae. I did the usual thing of brush it off to find it re-appears the next day or so. I wasn’t too pleased with the pool guy’s response when I asked him about the condition of the pool. He assured me all was OK. So I took a sample of water to Leslie’s and found there was no FC and the CYA was through the roof! So the pool guy was shown the door and I found this board. I managed to treat the mustard algae by raising the FC and shocking a number of times over 3 days. I also used yellow out.

Here are my current numbers:-
FC – 1.5
CC - 0
pH – 7.6
TA – 100
CH - Not known
CYA – 100+

My plan moving forward is Drain pool by a few feet to help reduce CYA level (I know I may have do this a few times) And to stop using the Chlorine tabs. I bought the Leslie’s FAS-DPD test kit so I can stay on top of the water testing.
My question is, should I reduce the CYA through draining or will evaporation and an auto leveler be enough over time to bring it down? I live in Southern California so we lose a lot to the sun/heat.

Thanks

CYA doesn't evaporate, so that won't work (Sorry!). I wish it would, cause then I could lower my CH the same way! Sorry to hear about the pool service debacle; unfortunately it's all too common. Once you drain and refill, post up some more test results (including CH) and we'll help you get squared away.

Or see if you can get an R/O treatment, to save water. They are not available everywhere, so you'll have to check your area.

You need to get your FC level up. It is dangerously low and an algae bloom is just around the corner

Water evaporates, but CYA and Calcium are forever.

2 ways to get rid of the CYA: drain, or reverse osmosis.

Where'd you get the numbers? A test strip, or drop testing? If it's a strip, I wouldn't be too hasty to drain yet. They're somewhat better than tasting the water, but not much. You might be below 100. Who knows?

If it's a drop test, try diluting your sample 50/50 with tap water, then mix it with the reagent, then get your reading and double it. If you don't know where you are, you won't know how much you need to drain to get to a reasonable number.

Yorba Linda's not that far from San Dimas... hmmmm...maybe a double R/O job during the off season could entice a certain firm to venture beyond San Diego and Riverside Counties...

I would hold off on the drain cycles you have planned. My CYA was above 100 and now it is down to 75ish due to rain, slpashout and my kid playing with the pump hose.
75 is good for me.