Why Drain Pool with High CYA?

[PoolBryce]

Thanks for the replies, Maddie and Kim.

Kim, what did you mean when you said, "To add it to your pool do NOT follow with something heavy on it) right in front of your return."

I think you two covered both my questions except about CH. My CH is 170. The Taylor test kit says this is good, but PoolMath says I actually need to be 250-350. Is PoolMath correct here for a plaster pool?

Thanks again,
Bryce

Kim's note-boy did I bugger that one up! It should say "To add it to your pool do NOT follow the directions on the bottle! Put it in a sock(s). Tie it off and hang it (use a broom stick or such with something heavy on it) right in front of your return."

 

[YippeeSkippy]

Take it up! If your water isn't saturated with enough calcium, it will actually leech it out of the wall plaster. So take the water up to the minimum recommended amount of 250.

In your part of the country you'll find the CH increases on its own with evaporation, and some of the fill water there is pretty hard already.

Maddie

 

[DeanP66]

Stay away from the pool store. Trust your numbers, especially since you've checked them twice with same results. Your TA is a little high, but don't worry about it for now. Get all your other numbers in line first and then see where you're at. If you do need to lower TA later, just add enough muriatic acid to lower pH to 7.0. This will drop TA some as well. Then you need to raise the pH back up to 7.6ish by aerating the pool. This will leave TA alone and only affect pH. Then you just repeat the process until you get TA to where you want it.

Be carefull when adding CYA. Even though you don't see any in your test, you could still have some in there up to 20 PPM. The test won't read it below that number. Since you're in AZ, you definitely want to run CYA on the higher side (50 or 60PPM) to keep the sun from burning off the chlorine too quickly.

As for CH, yours could be a little low for a plaster pool, but, since your in AZ where the water is usually very hard, you could probably be just fine leaving it alone, as long as you maintain your other numbers (pH, TA) in the right range to keep the CSI between -.3 and +.3. Your CH will climb fast enough on its own with all the additional water you'll add over time. There's no need to help the process by adding anything yourself.

 

[cfherrman]

I would add 30 ppm worth of cya and retest a week later, that will give you 30-50 cya in the end which is fine.

 

[PoolBryce]

Good afternoon, everyone.
Several months after my drain and refill and things are going great. No algae or other problems to speak of. However, just this week, my daily chlorine use has gone from about 2ppm/day to ~4ppm/day (it's starting to get real hot here). My CYA is currently at 30ppm. I've read on other posts on this site that 4ppm/day is reasonable considering the heat and sun here in Tucson. Does it make sense to anyone here to bump up my CYA a bit in order to reduce my daily chlorine use? Right now, I try to keep about 5ppm chlorine in the pool every day (per poolmath), and my daily-use test kit only reads up to 5ppm, so if I add CYA and then have to maintain a higher chlorine level, I'm not sure how I would measure that.

So two questions:
- Is it worth increasing my CYA a bit?
- If so, how would I measure my new chlorine on a daily basis? Would I need a different test kit, or should I dilute the pool water with tap water. If doing dilution, how does one do that accurately?

Thanks again for all the help. This forum has save me a ton of money and stress.

Regards,
Bryce

 

[triptyx]

Yes, start by boosting CYA to 50. I just did this a few days ago for the same reason.

On a daily basis, use the FAS-DPD powder test track your chlorine and add as needed. Another Tucsonan on the board here runs CYA at 70 or even 80.