High pH, low CYA, ammonia?

Jul 8, 2012
14
Northampton, PA
Long and difficult month of pool maintenance with no circulation and I have a dark green pool on my hands. Long story short I did rigid PVC plumbing, cracked the eyeball return fitting from torqueing to hard on the male pvc fitting, replaced that, found a big tear in my vinyl liner, patched it, pump seal developed a leak.... etc etc.

Anyway I'm finally leak free and started the SLAM process today. I have a few questions though. My pH reading originally came out a dark magenta, like a deeper color than 8.2 on the TF-100's basic test. So I added enough HCl to go from 8.2 to 7.4, tested it again an hour later and it was the same color. So I added the same amount again, tested again and still way high??? My other strange result was my CYA was practically non-existant. Slightly cloudy in the tube but filled it all the way to the top without blocking out the dot. My CYA to close the year was 40, but I did lose a bunch of water and refill a few times. So, I have a sock floating in front of the return with the amount to bring it up to 30 ppm from what I'm guessing was approx 5 ppm to start. Is the high pH and low CYA indicative of a conversion of last years CYA into ammonia? If so, what level should I be targeting to SLAM, regular SLAM or mustard algae SLAM? I am slamming the pool right now based on 30ppm CYA and the green is already fading to gray, and the FC is dropping dramatically pretty quickly. I targeted 15 ppm and like an hour later it was 8.5 FC and 1.5 CC. The high pH is what really worries me. Now that I started to SLAM though I know the pH result could be off. Could it be a reagent issue or can my pH have really climbed to such a caustic level over the winter? The t-100 kit is a new one from this spring.

Sorry I know that is alot of questions but I'm a little stumped and quite honestly pretty frustrated with this season so far. Could be worse though, my neighbors pool walls busted during the thaw this year. I'm going to crack open a cold one and await some respones.

Thanks
 
You need to get the PH figured out fairly quickly. Make sure the FC level is below 10 when testing PH. Very high FC levels can completely incapacitate the PH test, resulting in a strange color that has nothing to do with the actual PH. The PH reagent can go bad from excessive heat or sunlight, but if it is new this spring that is exceedingly unlikely.

I doubt you have ammonia. Ammonia converts nearly all of the chlorine you add into CC. If you had significant amounts of ammonia your CC level would be far higher.

Target regular SLAM levels.

Could you post a complete set of test results and tell us what the water looks like?
 
Tested this morning.
FC = 10.5
CC = 1.0
pH test didn't run because fc was over 10
Added cya to get to ~ 30ppm, will test again in a week
TA = 60 low I know but last season pH held best around 70ppm

Water is very cloudy and grey now after one day of SLAM. Was very dark green to start. Filter pressure goes up to backwash level after a few hours so I've been backwashing frequently. May try vacuuming to waste this afternoon to get rid of organics on the bottom.
Should I stop Slaming for now to let FC come down and concentrate on pH?
 
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