Just Drained the pool - Help me geset my CYA level

[dombey]

Hi Guys,

I just bought a house and it is my first pool (yay).
Unfortunately it came with 320ppm of CYA.
I just drained it & it is refilling as I type.

I live in Phoenix, AZ and the pool get probably 11-12 hours of direct sun depending on the time of year, and obviously it is intense. The water will get very warm in the summers.
I've read in the pool school that the CYA level should be 70-80 or higher if there is a lot of sun.
My question is...what do you recommend for a CYA level in Phoenix? (don't say 320!)

I'll be using just liquid chlorine instead of the tablets that likely were responsible for this situation in the first place.
Thanks guys!

 

[frustratedpoolmom]

Edit: I don't normally recommend this as a typical level - but considering your location I think 70 is a good level for you. And if you have a sand filter that level should slowly drop over time...

Just be sure you stay above the "min" level for your FC at all times. Because if you develop an algae problem, the higher CYA levels mean you'll need alot more chlorine to deal with it than you would at a lower CYA level. End edit.
Welcome to TFP!

 

[Bama Rambler]

Welcome to TFP
I started to write that your CYA should be 320 but that wouldn't have been funny would it?

I think I'd start with the CYA about 50 and creep it up from there depending on your FC loss.
How do you test your water?
Have you tested your fill water?
Can you post a full set of test results?
Tell us more about your equipment and pool.

 

[Butterfly]

Welcome to TFP

The CYA of around 70 seems to be common for your area.

We have members in your neck of the woods that will chime in soon.

Along with the tests requested, could we see a pic? :-D

 

[dombey]

Welcome to TFP
I started to write that your CYA should be 320 but that wouldn't have been funny would it?

I think I'd start with the CYA about 50 and creep it up from there depending on your FC loss.
How do you test your water?
Have you tested your fill water?
Can you post a full set of test results?
Tell us more about your equipment and pool.

thanks for the quick responses guys!
I have a full dpd kit from leslie's (it's a taylor).
I haven't tested the fill yet; it's only been going for 5 hours at about 10 gal/minute...it's gonna be a while (28k gal).
I'll take some tests this evening as the pool approaches 1/4 full...ha

EDIT: about the pool:
-28k gal
-DE filter
-usually has a 4 year old Vizsla guarding it (ie begging strangers to throw the ball in the pool for her)

 

[baudilus]

320ppm of CYA.

 

[dombey]

ok the pool is finally full after 44 hours of double hoses...

I've been adding liquid chlorine and muriatic acid to keep it in the ballpark until I have the time to do a full test- I'll do a full test of everything tonite and post my results...I want to get this thing set up right from the beginning...

 

[frustratedpoolmom]

"Full" test? Please don't take this the wrong way but you are testing FC and PH before adding either chem, correct? We don't advise blind additions of chemicals - too risky. It's not clear to me from your post if you are testing these or not.

 

[Butterfly]

It would also be helpful if you tested your fill water for pH, TA,& CH and posted that info.

Please add your pool and equipment specs in your signature and your location in your profile.
You can go to User Control Panel, upper left under TFP logo, and select Profile.

 

[dombey]

"Full" test? Please don't take this the wrong way but you are testing FC and PH before adding either chem, correct? We don't advise blind additions of chemicals - too risky. It's not clear to me from your post if you are testing these or not.

Ha, yes I've been testing them before adding (and 1 hr after with pump running). It's my first pool but I like to do a lot of reading before I do anything....so I'm not completely helpless.

I just haven't had time to do every test that comes in the kit in the last 14 hours (that, and I had nothing on hand to do anything with the numbers). I did the FC and PH tests because they are quick and I had the chemicals on hand - and I didn't want to leave the pool with no chlorine, especially since it had two days of accumulated leaves, bugs, and dirt in it (couldn't run the pump, etc when filling).

FC reading on the fill water showed as zero, PH came in at 8.0.
I added chlorine to bring up to 6 ppm (would have gone higher to shock but ran out of chlorine-with very little CYA in the water I'm probably near shock levels anyways, right? I'm sure this will be near zero by the time I get home); brought the PH down to 7.3 with muriatic acid.

I'm expecting pretty hard water given that I'm in phoenix, and the previous fill water was (don't remember the exact number) very hard.
My TA on the old water was high also, but on the Taylor site it gave a formula for taking CYA out of the TA equation, which landed me at a more reasonable number. (site: http://www.taylortechnologies.com/Chemi ... ontentID=5 )
Really, who knows what was done to that pool though, so we'll see where it all comes in tonite.

 

[frustratedpoolmom]

Good - I figured that was the case but I didn't want to assume that and believe me, I've heard just about everything on this board....

You are doing the right thing (and I rarely run a full test. TA perhaps once a month, PH every few days... my levels stay pretty stable.) You'll get to know your pool and establish a comfortable testing routine. We tell people not to shock higher than 10 with 0 FC.

 

[PaulR]

My TA on the old water was high also, but on the Taylor site it gave a formula for taking CYA out of the TA equation, which landed me at a more reasonable number. (site: http://www.taylortechnologies.com/Chemi ... ontentID=5 )
Really, who knows what was done to that pool though, so we'll see where it all comes in tonite.

If you get in the habit of using the Pool Calculator then you should give it the unadjusted numbers, because it takes that stuff into consideration automatically. And ditto for posting numbers here; some of us keep it running on the side, and when somebody posts a set of test results we'll plug 'em in and see what pops out. If you post adjusted numbers then our advice might be off.
Thanks!
--paulr

 

[dombey]

My TA on the old water was high also, but on the Taylor site it gave a formula for taking CYA out of the TA equation, which landed me at a more reasonable number. (site: http://www.taylortechnologies.com/Chemi ... ontentID=5 )
Really, who knows what was done to that pool though, so we'll see where it all comes in tonite.

If you get in the habit of using the Pool Calculator then you should give it the unadjusted numbers, because it takes that stuff into consideration automatically. And ditto for posting numbers here; some of us keep it running on the side, and when somebody posts a set of test results we'll plug 'em in and see what pops out. If you post adjusted numbers then our advice might be off.
Thanks!
--paulr

Alright guys got the full battery of tests done just now:
FC: 0.5 (it burned off nearly everything today without any CYA). didn't run the CC and TC
PH: 7.6
TA: 105-110
CH: 240
CYA: way below what my test will show (min 30 ppm). Based on previous concentration and guesstimates of how much water was left in my pool when I drained it, I'm guessing about 5ppm.

I'm planning on 1 gal of 10% liquid chlorine...since I don't know my CYA level and the CYA I put in will take time to dissolve, I'm going a little lower than I may need to once the CYA is up and running.
Just added CYA according to pkg directions to obtain about 30 ppm of CYA. I'll give that a week before adjusting...that stuff scares me so it will be a long process dialing it in.

Sound reasonable?

 

[PaulR]

Sounds reasonable. While you're waiting for the CYA, I would add the chlorine in the evening, after the sun is off the pool, to give it the most chance to work before the sun starts burning it off again next morning. Figure on adding it every day until the CYA gets up there.
--paulr

 

[dombey]

Sounds reasonable. While you're waiting for the CYA, I would add the chlorine in the evening, after the sun is off the pool, to give it the most chance to work before the sun starts burning it off again next morning. Figure on adding it every day until the CYA gets up there.
--paulr

Cool - thanks!

 

[frustratedpoolmom]

If the CYA is granular... what do the package directions say?

 

[dombey]

If the CYA is granular... what do the package directions say?

for 6,000 gallons to add 40ppm, use 2 lbs.
It said to throw it in a bucket of hot water and mix into a slurry, then pour into the skimmer very slowly while the pump is running.

I have 28,000 gallons, and I put in 2 lbs because I'm all about taking it slooooowwww.


(note this doesn't match what I write above about adding enough for 30 ppm)...what I meant above was that I was going to shoot for 30ppm and work my way up from there if the FC is burning off too quickly. I'm sure it will, but part of this whole thing is understanding/experiencing what happens when you change things...

 

[frustratedpoolmom]

The hot water/slurry rarely works, often the stuff doesn't dissolve good enough.

We recommend the "sock method" here - it allows you to add it and not worry about wether you have to backwash your filter. Just put 2lbs in a sock, yes, the kind you wear and tie a knot at the top. Then using string to hold the sock, tie it off in front of a return where it dangles in front of the flow of water. It will dissolve out of the sock. Use a heavy brick or something to tie the string to.

 

[dombey]

The hot water/slurry rarely works, often the stuff doesn't dissolve good enough.

We recommend the "sock method" here - it allows you to add it and not worry about wether you have to backwash your filter. Just put 2lbs in a sock, yes, the kind you wear and tie a knot at the top. Then using string to hold the sock, tie it off in front of a return where it dangles in front of the flow of water. It will dissolve out of the sock. Use a heavy brick or something to tie the string to.

Good idea.
Wouldn't the granules just dissolve even if they got caught in the filter? (eventually)
I'm wondering how long it would take to dissolve that stuff if you took say a drill and paint mixer to it in a bucket...nothing like instant gratification.

 

[frustratedpoolmom]

Kinda just depends. It's a good idea to run the filter 24/48 hours non-stop if added directly. Many people don't do that and forget the pump's on a timer. Its especially problematic when one is trying to clear a swamp and they need to backwash fairly often if its still dissolving in there it can go out with the backwash.