CYA how much?

[LVChris]

I just drained and refilled my pool this week and need to add stabilizer to bring the CYA up and want to make sure I'm understanding the pool math correctly. My CYA value is zero at this point and it says to add 123 oz by weight and I'm calculating 7.7 lbs. My other values are: FC = 5, pH=7.5, TA=110. Thanks!

 

[Texas Splash]

Chris, what CYA goal were you shooting for? When I check on the calculator, going from zero to a CYA of 40 requires 117 ounces (7lbs 5 ounces) of granular stabilizer. Is that about what you were trying for?

 

[LVChris]

Hi Pat, Pool math says to shoot for 30, is that correct?

- - - Updated - - -

Sorry, it says 30-50. Yes, that's what I need then I guess. I assume this will take awhile. I've added about 1lb to two socks and placed it inside the skimmer basket.

 

[Texas Splash]

You'll find that as summer approaches, you may increase CYA even more to protect your FC from that blistering Vegas-Valley sun. I know, some of my childhood freckles are from there. After the stabilizer has dissolved, I would test CYA in about 2-3 days. If you reached your goal and FC usage each day is minimum (no more than 4 ppm), then you're good. Keep the water algae-free and when you see FC drop more & more each day as summer approaches, that's your clue you may need to increase CYA a little more.

 

[LVChris]

Thanks Pat. It's my understanding the CYA level should never go above 50, is that right?
Yes, the sun here can be really brutal as you know! I was going through a ton of bleach last year and even resorted to floating some of the pucks to get the CYA to go up. I don't know why I didn't go this route first :-(.

 

[Texas Splash]

30-50 is the general TFP recommendation, yes. However .. ..... there are a few exceptions for locations along certain longitudes that are simply known for more intense UV exposure. Places like TX, AZ, FL, S CA, etc and some others take a beating each summer - especially if there is no shade on the water all day. Mine is one such example. I maintain a steady 60-70 CYA in the summer to keep my FC losses to about 2-3 ppm per day. But just like SWG owners who have high CYA levels, it's critical we always watch our daily FC to ensure we don't give algae a chance to attack or we end-up with a high SLAM level. So when you know your pool is TFP-clear & algae-free, if you lose too much FC each day you may have to increase CYA just a bit.