CYA above 140

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Keepinitclean

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Sep 15, 2012
11
Hello

Just starting out in the pool business and I have a customer with CYA at a hi level. I took my reading with the Taylor k2006 and with the colorQ pro 7 both read Hi. My customer has a 19000 Gallon pool so I drained 6500 Gallons the other day and refilled it. I ran the filter the normal 8 hrs and went back to take a reading. The CYA level is still reading HI. So my question is will draining another 6500 Gallons of water solve this problem or will I be wasting more time? Also I'm reading to many different way to add acid to a pool to lower Alkalinity could you please tell me the proper way to pour acid in the pool for Alkalinity...Thanks
 
Welcome to TFP !

You need to be more specific with the CYA level. What reading are you getting with the K2006? If it is over 100ppm, try diluting the pool water 50/50 with tap water and redoing the test, doubling the reading. You can then determine the % of water replacement required to let it to a certain level.

For the TA reduction, there is an article in Pool School that describes the process. Basically using acids to lower pH and TA and then aerating to raise the pH back up so you can add more acid ... and repeat.

The slug method for TA reduction is a myth and can damage the pool. Just pour the acid slowly in front of a return.

Posted from my Droid with Tapatalk ... sorry if my response is short ;)
 
Use a dilution test using 1 part pool water to 1 part fresh (2 parts, or 3 parts etc etc) water to get a true CYA reading, there's no point in saying if I drain x, as you really need to know albeit roughly what the current CYA level actually is. Draining 50% of the pool water will lower the CYA level by that amount and so on.

As for your question regarding adding acid to a pool we generally recommend dissolving it in a bucket before adding it in front of the returns (or water inlets) to the pool.

Regards
Stuart
 
Ok thanks for the tip! Next time I go I will do the 50% on the cya test. The reason I asked about the acid is bc the guy that tought me said to pour the acid in a circle in the deep end. Now I know that doesn't matter.

Sent from my SCH-I535 using Tapatalk 2
 
Ok I went back to my pool today 19000 gallons and after draining 6500 gallons my CYA at a 50/50 with tap water and pool water reads 100. So I guess we are talking a 200 CYA count. On that note does this mean I must drain at least 50% of the pool water or maybe 75% of the water? I just got this acct so it won't look bad on my part if I tell my customer he needs to drain more water.
 
Keepinitclean said:
Ok I went back to my pool today 19000 gallons and after draining 6500 gallons my CYA at a 50/50 with tap water and pool water reads 100. So I guess we are talking a 200 CYA count. On that note does this mean I must drain at least 50% of the pool water or maybe 75% of the water? I just got this acct so it won't look bad on my part if I tell my customer he needs to drain more water.
Click to expand...

If you hit 100 at 50/50 - try 1/3 pool water and 2/3rd's tap water and verify that you come in somewhere around 30-35. Multiply the result by 3 and see where you are. I'm afraid if you hit 100 with 50/50 it could be worse than 100 still. Absolute accuracy of the test is low (+/- 15ppm with undiluted samples), but better than guessing.
 
That means you could be anything over 200ppm. I would say at least another 75% water change needs to be done. You could try the test again with 2/3 tap and 1/3 pool water and triple the reading, but you are loosing a lot of accuracy.

UWV a little faster ... this time ;)
 

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How was the last test done? I am not sure how well the colorQ does on CYA (there are many reports in the forum about it). I would stick to the turbidity test that came with the K2006 (although I am guessing you are out of reagent since it comes with so little).

You can get refills from tftestkits.net that are much larger.
 
Taylor or colorQ? Mixing the results between the 2 test might get confusing.

Taylor using 50/50 = 100*2 = 200ppm
? using 33/66 = 50 * 3 = 150ppm

If it was Taylor, I think a 75% change is in order as you are likely between 150-200.
 
Keepinitclean said:
I used the Taylor on all the test for this pool
Click to expand...

Just for grins - might be worth taking ColorMote tests at 100% pool water, 50/50, and 1:2 ratio's to see how closely it parallels the CYA test in the Taylor kit.
 
Keepinitclean said:
I don't see how a pool guy could have let it this high. Thanks for your help and the fast response time.
Click to expand...

What exactly are your plans here? Just clear it once? Perform weekly service? Perform daily service?

It is not uncommon for pool services to elevate the CYA to around 100ppm (or more) intentionally. This is because they only show up once a week (or sometimes every 2 weeks here). They come and jack the FC WAY high, and need the higher CYA level to protect it from the sun so it does not drop too much before they show up again in 7-14 days. They just hope the the FC stays high enough that the pool does not turn green before they come back (although it may have dropped lower that we would recommend). Then they shoot the FC way high again which kills off anything that may have started to grow and the hope they are good in 7-14 days again.

This forum is more about daily maintenance for pool owners. If you are looking to do weekly service, you may need to adjust some of the recommendations found here.
 

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