Plaster Pool Mesa Arizona - Need some emergency advice for today

[Sunny Blues]

Hello all,

I am posting on behalf of my brother who I am visiting in Mesa. I saw his pool had scale, possibly algae too, albeit the water is clear, and he used tons of trichlor pucks in the past. I have started to teach him all the BBB wisdom.

We are in somewhat of a hurry for guidance today because he is driving me back home to the Chicago area tomorrow and that leaves his pool possibly unable to be used by his family until he returns if I don’t guide him best.

His CYA is off the charts. It must be well over 250 because 1/4” of water in the tube completely blocks the black dot, and the water level is like 1” below the 100 line.

Chlorine is 0
TC is .5
pH is 6.5
Alkalinity is 230
CH is over 1000

We need to shock it but at minimum that is a 40 if the CYA were just 200. It’s probably a lot higher. Target would be 24. His test kit only shows chlorine up to 5 ppm because while it is a Taylor kit made for Leslie’s pool, it doesn’t have the powder or instructions to test by drops, only by color comparison. It only has R-0001, R-0002, and R-0003. I don’t know how to guide his wife to test the chlorine levels while we are gone to keep them in safe ranges for the CYA levels.

1) How do I test to get an accurate CYA reading with this kit?

2) How long does it take for a chlorine level of 40 to drop to 24 in AZ Sun with ungodly CYA levels?

3) Is it possible to use this kit to ascertain actual FC at levels of 10-40? Is the chlorine drop test powder and R-0871 sold at local stores?

4) Will the target FC of 24 be dangerous to swim in? He has nine grandkids that I don’t want hurt.

5) I can have him wait until he gets back to drain and refill to bring the CYA down. But he needs to get the pool swim-able before he leaves. So maybe we don’t shock? Just add what pool math says we need to get it to 24?

Thanks for your help!
Juju

 

[mknauss]

You can do an extended Cya test. Use 1:1 pool water and tap water. Mix that then use it for pool water in test. Double the results.
A couple days I would think.
Doubt you will find FAS DPD in a store. Cut pool water using distilled water and multiply the results.
If cya above 60 ppm, 24 ppm fc is no issue.
That sounds best. The pH is big issue. Needs to be in 7’s. The TA number makes no sense with that pH.

 

[JoyfulNoise]

If the CYA is over 200ppm then the shock level would be 80ppm FC, not 40.

Sorry, that water is toast. The pool needs to be drained and refilled. However, in this heat, you risk serious plaster damage. There is no way to fix that pool quickly and no one should be swimming in it at all. It’s unsanitary. Tell him to register an account here and when he gets back we can help.

 

[Sunny Blues]

You can do an extended Cya test. Use 1:1 pool water and tap water. Mix that then use it for pool water in test. Double the results.
A couple days I would think.
Doubt you will find FAS DPD in a store. Cut pool water using distilled water and multiply the results.
If cya above 60 ppm, 24 ppm fc is no issue.
That sounds best. The pH is big issue. Needs to be in 7’s. The TA number makes no sense with that pH.

Thank you. I mistyped the pH number. It is 7.5.

 

[mknauss]

Heed what Matt said above, I answered your questions, he told you what you should do.

 

[Sunny Blues]

If the CYA is over 200ppm then the shock level would be 80ppm FC, not 40.

Sorry, that water is toast. The pool needs to be drained and refilled. However, in this heat, you risk serious plaster damage. There is no way to fix that pool quickly and no one should be swimming in it at all. It’s unsanitary. Tell him to register an account here and when he gets back we can help.

Thank you. Yes I think I read 40 from the cya chart here but that was for a CYA of 100.

Ok. I appreciate the help. He will have to wait to shock until he returns.

 

[JoyfulNoise]

His pool water is fairly typical in AZ because all the pool stores give lousy advice and tablets are sold by the hundreds of pounds here in all the big box stores. Costco recently had a huge pile of Clorox XtraBlue tablets (40lbs for $190) stacked probably 8 buckets high and they were sold out within 2 days. The amount of trichlor used here in AZ is ridiculous and it not only causes high CYA but leads to very low pH water.

 

[Sunny Blues]

You can do an extended Cya test. Use 1:1 pool water and tap water. Mix that then use it for pool water in test. Double the results.
A couple days I would think.
Doubt you will find FAS DPD in a store. Cut pool water using distilled water and multiply the results.
If cya above 60 ppm, 24 ppm fc is no issue.
That sounds best. The pH is big issue. Needs to be in 7’s. The TA number makes no sense with that pH.

Thank you again.

So with the diluted test the CYA is at least 300. The dot disappeared about 1/2”-3/4” below the 100 marking. So I figured 150x2?

He is draining it right now that it is in the shade for the rest of the day but will probably only drain 1-2 feet, and then he will drain 1/2 the pool again when he gets back and maybe 1/2 again in the fall. He doesn’t want to drain completely all at once because it’s July in Mesa and extremely hot and that could damage his plaster.

He will be creating an account himself. We are dealing with a lot today because my son is missing, has been since June 2nd, and it’s stressful. I came out west last week where his car was abandoned in CA and am driving it back home to keep it safe. My brother is busy today arranging time off work to get me home safely as well as trying to get his home and pool prepped for his absence, so he doesn’t have time himself today. That’s why I posed the questions on his behalf and took on the pool task to help him.

This community means so much to my husband and I, and saved us over $24,000 in the past 12 years, probably more. We have never had any serious pool problem since converting. I just knew I could help my brother with his pool in return for his kindness if I posted here. And as always I received wonderfully helpful replies almost immediately by multiple people.

Thank you

 

[mknauss]

Instead of multiple drains, he can do the water exchange. But needs a couple days to do it.

Draining - Further Reading

www.troublefreepool.com

 

[Newdude]

We are dealing with a lot today

You have my well wishes until you tell me you don't need them.

 

[Sunny Blues]

Ok couple more questions:

I attached a rough sketch of his plaster pool shape and size. I needed better than his guesstimate of 10,000 gallons of water, so I calculated volume using a kidney shaped pool. The small 7’ circle is an attached hot tub that shares the water. I came out to a total of 15,000 gallons using the online calculators and math. Huge difference.

Last night we drained 2’ from his pool. It is then added back fresh water. We added 8 gallons of 10% liquid chlorine. Before adding the water was somewhat green but you could still easily see the bottom. This morning it is crystal clear but the entire surface of the plaster has brown/black and grey stains on it. Large black splotches in some spots. All over grey marveling effect. Brown stains ta some spots. Holding a puck to it for 5 minutes or scrubbing it did not remove. A large vitamin C tablet left to dissolve on another spot and then scrubbed into it did not remove.

This morning I used the 1:1 diluted method to measure CYA and the results are identical to yesterday’s dilution test - so it was well over 300 then and probably now. I have no way of knowing how much higher.

1) We know we has to completely drain and refill to get a handle on this. But for now we want to maintain a high enough chlorine level until he gets back home on Sunday or Monday.

2) Is it possible to do the CYA test with a 1:3 tap water dilution and multiply results by 4? Or a 1:4 dilution and multiply by 5? Or is that less accurate than a 1:1?

3) I diluted a 1T sample of pool water with 8T of distilled water and did the chlorine test, (color comparator that maxes out at 5 ppm). I multiplied results by 9. Did I do that correctly? Using 9 as multiplier? The results were a 2 making the FC 18. I find it very hard to believe that 8 gallons of 10% chlorine into a 15,000 gallon pool would already be down to 18 ppm only twelve hours later.

4) how to remove ugly staining? Is replastering his only hope? Will chlorine eventually get rid of them?

Thank you!

 

[mknauss]

Is it possible to do the CYA test with a 1:3 tap water dilution and multiply results by 4?

Yes. it will be less accurate.

I multiplied results by 9. Did I do that correctly? Using 9 as multiplier? The results were a 2 making the FC 18.

Sounds correct.

I find it very hard to believe that 8 gallons of 10% chlorine into a 15,000 gallon pool would already be down to 18 ppm only twelve hours later.

Me too. that was 53 ppm FC you added. Things get weird with testing, etc at high FC levels.

how to remove ugly staining? Is replastering his only hope? Will chlorine eventually get rid of them?

Sounds like some or all are metal. Likely copper and or silver. Any ionizer devices used (PoolRx) or copper algaecides/pucks with copper (blue in the name)? Replastering is best to get rid of them. Then follow TFPC.

 

[ajw22]

If you need to dilute the pool water further then apply these ratios:

Pool water	Tap or distilled water	Multiply result by
1	1	2
1	2	3
1	4	5