CYA not Showing up after adding

[scader]

To revive this thread with the same issue (as I don't see a final solution yet): I ran out of 0013 (it's now on order), so I took a sample to Leslies and they measured CYA at 0. I added 7lbs of stabilizer to the skimmer (premixing with water in bucket). The next trip Leslies's six days later measured it at CYA at 10. I haven't back-filertered or anything since adding, and, expectedly, the SWG is having a hard time keeping up. I need to self-test once reagent arrives, but is what is the typical amount to get CYA up to 50-60 from 0? Should I add more?

 

[Texas Splash]

A 21K pool would need 8 lbs 12 ounces to get from zero to 50 according to PoolMath. Just be careful to not go to high before your refills arrive.

 

[scader]

Thanks. That's why I'm puzzled: I added 7lbs and it went from 0 to 10 (as far as I can trust the pool store). I would assume the affect of adding stabilizer is fairly linear, and 7lbs would have been closer to 40? Not target, but better than 10.

Is there any reason that stabilizer wouldn't raise CYA as expected?

 

[mknauss]

Pool store testing.

Wait for your reagent to test CYA yourself.

 

[scader]

Okay, got more CA regeant, and sure enough: practically 0 CYA. I have the K-2006 test kit, and I had to fill it all the way to the top before I couldn't see the dot (all 14mL from the shaker bottle). Technically, the last reading is 30ppm, so I don't know if I should assume the very top is 0ppm?

So, again, odd, given that I already added 7lbs of stabilizer. I guess I'm due for another round? Should I calculate from 0ppm?

The whole thing started because I have to run the pump and SWG on high 24/7 just to maintain 1ppm FC. Given that's been going on for over a week, I think I might need to SLAM--the pool looks relatively clear from the surface, but seems otherwise cloudy when wearing a mask underwater. Should I SLAM before adding the CYA, so I'm adding less chorline?

 

[mknauss]

Have you opened the filter to see if any CYA powder is trapped in it?

Once that is checked, Add 30 ppm CYA powder using what we call the sock method. Get an old sock (no holes) and put the measured amount of CYA you need. Tie the sock closed and either suspend it in front of a return (hang it from your brush pole works with something weighted on the deck) OR if it still allows flow thru the skimmer, place the sock in the skimmer. Every 15/20 minutes give the sock a squeeze to speed up the process. Please DO NOT follow the directions on the container of CYA to just pour it into the skimmer and don't just toss the sock in the pool as the CYA is acidic and can bleach/stain pool finishes.

Once that is dissolving, run a Overnight Chlorine Loss Test tonight or tomorrow night. If you fail that test, then SLAM Process. If pass, test your CYA 24 hours after the powder in the sock is dissolved and then add more to your final CYA level you wish to attain.

Take care.

 

[borjis]

Putting it in through the skimmer, while that seems correct as the instructions say, it could take up to two full weeks
before it finally all registers on the test.

The sock method as Mknauss suggested is the best method. You can have it fully dissolved and fully registering on the test within 2 hours or so.
The cya will get gummy within being in warmish water about 20 minutes. if you squeeze and massage continuously til the sock is empty it's done
and ready to test about an hour later with the pump running.

Since you already added to the skimmer you should either backwash it out, or leave it in there and wait a week or two then test.

be careful how much more you add though keeping in mind what you already added through the skimmer, so you don't overshoot the cya level you want.

 

[scader]

Thanks, all very helpful. I think I want to inspect and backwash, then go for the sock method.

To "open the filter" do I remove the hex on top of the value selector and remove parts until I can peer down inside?

How would I know when backwashing was affective? Looking inside, or just backwashing for X amount of time?

I'll do the sock in 30ppm increments to see if it's more affective.

Since I only have 1ppm FC, that means the follow morning I should look to see if I have 0ppm for the OCLT, right?

Thanks again.

 

[mknauss]

You would want to raise your FC to at least 5 or preferably 10 ppm at the time of the OCLT. Just add the chlorine and let the pool mix for 30 minutes and then test FC and record it. Be sure the pump is on for 30 minutes in the AM (before the sun hits the pool surface) for that test. Do a CC test on that one.

 

[scader]

Okay, here's the update...

I incidentally overfilled the pool and it rained, so I had ample water to backwash to get any and all previous attempts of CYA out.

Then, in the late evening, I dumped enough liquid chorline into the pool to get 5ppm FC; I think three bottles, first round was two bottles, then I waited half hour and measured 3ppm FC. Then I added another bottle to bring it up to 5ppm FC after waiting another half hour. By this time it was midnight

The following morning it was back down to 3.5ppm, but I was concerned I might have measured wrong, or not measured early enough, so I waited until just after sunset and added more to get it up to 7ppm FC. I also added 4lbs of stabilizer earlier that day to get it up to 30 CYA. I used a modified sock method, instead using an old t-shirt (see photo below) so it hung in front of the jet. It was fun to watch the stabilizer slowly drift out of the shirt. Also nice to know exactly how much had been dispersed.

This time it read a consistent 7ppm the following morning--no loss. So either I killed off the alergy from the first night, or I miss-measured. That day I also added another 3lbs of stabilizer and now the pool is at 50 CYA.

At this point I turned on SWG, and waited a few days, and finally I get an expected FC amount without other intervention.

Given SWG, I should continue adding stabilizer to bring CYA up to 80, right?

 

[mknauss]

70 or 80 ppm CYA assists your SWCG in maintaining a proper level of FC.