CYA off the charts

[Amail]

Got my Taylor K2006 last Friday and got to prepping for a Saturday pool party. The pool had been covered for three days and I was alarmed to see so much green on the floor. I filled a pitcher with water for testing after I finished vacuuming, then set about cleaning up. It was surprising how easy the algae vacuumed up. Didn't need much brushing.

Once everything was clean it was time to break out the kit. I first took readings with the old kit using the pitcher water and then a fresh sample to see if there were any difference; I didn't see any.

Old Kit Readings
Date Temp​	7/10/15 87°
FC​	3.0 - 4.0
pH​	7.6 - 7.8

New Kit Readings
Date Temp	7/10/17 87°
FC​	8ppm
CC​	.8 ppm
pH​	7.4
TA​	240
CYA​	one bajillion

I've got no idea what my CYA levels are. I filled the bottle to the 7mL line with water, then added R-0013 Cyanuric Acid Reagent to bring it to 14 mL, shook it real good, and started pouring it into the smaller of the integrated vials. I don't think I managed to put more than a half inch in before the black dot disappeared. It appears the markings are a logarithmic scale, so I'm guessing my CYA must be 1000. Not sure I believe this since I dumped about half the water a year or so ago.

Now what?

 

[Mike1162]

Try mixing 2oz pool water with 20oz tap water. Mix & retest CYA. Multiply reading by 10.

 

[Amail]

The instructions are:

1. Rinse and fill CYA dispensing bottle (#9191) to 7 mL mark
with water to be tested.
2. Add R-0013 to 14 mL mark. Cap and mix for 30 seconds.
3. Slowly transfer cloudy solution to small comparator tube
until black dot on bottom just disappears when viewed
from top.
4. Read tube at liquid level on back of comparator block.​

Do you mean I should mix up the 2/20 ml solution, then pour that in to the 7mL mark?

 

[zea3]

Yes, he wants you to use a diluted sample to get an idea how high the CYA may be. It won't be as accurate as an undiluted sample, but it will get you in the ballpark. What have you been using to chlorinate the pool?

 

[Amail]

That makes sense. Would it be better to use bottled water instead of tap in case the city water has high CYA too?

I've been using chlorine from Home Depot for the last year and a half since jettisoning my pool guy. He was having a hard time getting the balance right and ultimately suggested we dump and refill half the water. Once that was done he was able to get things under control, but that was about the same time I decided I didn't need to pay someone for the service. Prior to that we used chlorine tablets from Costco exclusively.

 

[lefty51]

let's see how good my math is. 23K pool --- CYA = 1 bajillion........... I think you need to replace 193,745 gals to bring it down to about 40 ...give or a take a thousand gal :razz:

 

[Mike1162]

Either bottled or tap should be fine, neither should have CYA in it.
Is the chlorine from Home Depot liquid, tabs, granular?

 

[singingpond]

Drinking water (tap water) does not have CYA in it. However, no harm in using bottled water if you prefer.

The 1 to 10 dilution is pretty extreme. The initial suggestion on the forum is usually to try 1:1 or 2:1 plain water to pool water
to start with. Once you have your water mix, you use a sample from that mixed water to run the CYA test (just as you did before with your pool water sample).

If your CYA is really high, as yours is, you can save on the CYA reagent by not using the full 7 ml. The main thing is to get precisely equal parts of the tested water and the reagent. In other words, since you know that the dot disappears with half an inch of the water/reagent mix in the CYA tube, you could try (for example) 3 ml of water mixed with 3 ml of reagent. However, for this to work, you need to measure accurately. A syringe from the pharmacy works well to meter out a few ml of liquid.

I would only bother with this if you are short on CYA reagent, as you would be if you are using the K-2006 (typing inside the reply box here, I don't remember which kit you have). If you have the TF-100, I think you have more of the reagent to start with.

If you do 1:1 dilution, multiply result by 2; if 2:1, multiply result by 3; if 10:1, multiply result by 11.

 

[Amail]

Okay, put 2 oz pool water into 8 oz tap water for a 1:5 dilution. Added 7 ml mixture to 7 ml reagent and came up with a reading of 40 ppm. That time 5 gives me a CYA of 200. FC is 5 ppm, CC is 0. Not a happy camper.

 

[aasbury]

Okay, put 2 oz pool water into 8 oz tap water for a 1:5 dilution. Added 7 ml mixture to 7 ml reagent and came up with a reading of 40 ppm. That time 5 gives me a CYA of 200. FC is 5 ppm, CC is 0. Not a happy camper.

I am assuming you are under water restrictions at this time?

- - - Updated - - -

If you are unable to drain and refill you must keep the FC high enough for your CYA. It can be done, I did it several years ago. Here is the Chlorine/CYA chart

http://www.troublefreepool.com/content/128-chlorine-cya-chart-slam-shock/

- - - Updated - - -

Got my Taylor K2006 last Friday and got to prepping for a Saturday pool party. The pool had been covered for three days and I was alarmed to see so much green on the floor. I filled a pitcher with water for testing after I finished vacuuming, then set about cleaning up. It was surprising how easy the algae vacuumed up. Didn't need much brushing.

Once everything was clean it was time to break out the kit. I first took readings with the old kit using the pitcher water and then a fresh sample to see if there were any difference; I didn't see any.

Old Kit Readings
Date Temp​	7/10/15 87°
FC​	3.0 - 4.0
pH​	7.6 - 7.8

New Kit Readings
Date Temp	7/10/17 87°
FC​	8ppm
CC​	.8 ppm
pH​	7.4
TA​	240
CYA​	one bajillion

I've got no idea what my CYA levels are. I filled the bottle to the 7mL line with water, then added R-0013 Cyanuric Acid Reagent to bring it to 14 mL, shook it real good, and started pouring it into the smaller of the integrated vials. I don't think I managed to put more than a half inch in before the black dot disappeared. It appears the markings are a logarithmic scale, so I'm guessing my CYA must be 1000. Not sure I believe this since I dumped about half the water a year or so ago.

Now what?

Been there before...

 

[Amail]

Either bottled or tap should be fine, neither should have CYA in it.
Is the chlorine from Home Depot liquid, tabs, granular?

Sorry, missed your post! I'm using liquid chlorine, 10% hypochlorite.

 

[pabeader]

Any idea where all the CYA came from? Any pucks in a auto dispenser? Any 'shock'?

 

[Amail]

Bumping one of my old threads. In answer to padeader, yes, I used to use pucks all the time. And 'shock' too. That was before I left the dark side, but by then the damage was done. I'm still struggling with high CYA levels, but will drain and refill in the fall so I can get this water balanced nice and tidy. May even go with SWG by then, but I've got more researching to do first.