Water is finally crystal clear, but still high consumption of chlorine

ntbrink

New member
Aug 5, 2017
3
Indianapolis, IN
I've learned so much from reading these forums, but I'm a bit stumped now. Our family took a two week vacation in July, and although we had a friend come a couple times to check on the pool, we came back to a very cloudy pool.

We got home really late, so first thing the next morning I added eight gallons of chlorine, and then had to go to work. When I got home, I tested the water and got these results:
FC=.59
CC= 4.79
pH=7.1
Alk=150
CH=182
CYA=0

I started the SLAM, and went through TONS of chlorine - 30 gallons over the first 3 days. The water cleared up little by little. After four days, the clarity was back to normal. The combined chlorine has been below 1 for several days, but the pool is still consuming a lot of chlorine. I test and add chlorine first thing in the morning, mid-afternoon when I get home from work, and at night.

My latest test results today were:
FC=15.2
CC=0.5
pH=7.5
Alk=155
CH=188
CYA=35

I've been trying to maintain the FC at 14-16. I'm losing about 4ppm of free chlorine overnight the past several nights. And the FC seems to be dropping at a constant rate throughout the day as well. The past four days the water has been clear, but still consuming chlorine at a constant rate. I add 1-1.5 gallons each time I test (~3 times a day). I brush and vaccuum every couple days.

Any advice? Thanks!!!
 

jblizzle

Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
43,238
Tucson, AZ
:wave: Welcome to TFP!

What test kit are you using? Did you add cya? Can you list all chemicals that have been added to your pool?
 

ntbrink

New member
Aug 5, 2017
3
Indianapolis, IN
I'm using the Taylor K-2006 test kit.

I did add some stabilizer add the beginning to raise the CYA to 30-40. Other than that, I've added gallon after gallon after gallon of liquid chlorine.
 

nutshellml

Member
Jun 26, 2019
19
New Jersey
I've learned so much from reading these forums, but I'm a bit stumped now. Our family took a two week vacation in July, and although we had a friend come a couple times to check on the pool, we came back to a very cloudy pool.

We got home really late, so first thing the next morning I added eight gallons of chlorine, and then had to go to work. When I got home, I tested the water and got these results:
FC=.59
CC= 4.79
pH=7.1
Alk=150
CH=182
CYA=0

I started the SLAM, and went through TONS of chlorine - 30 gallons over the first 3 days. The water cleared up little by little. After four days, the clarity was back to normal. The combined chlorine has been below 1 for several days, but the pool is still consuming a lot of chlorine. I test and add chlorine first thing in the morning, mid-afternoon when I get home from work, and at night.

My latest test results today were:
FC=15.2
CC=0.5
pH=7.5
Alk=155
CH=188
CYA=35

I've been trying to maintain the FC at 14-16. I'm losing about 4ppm of free chlorine overnight the past several nights. And the FC seems to be dropping at a constant rate throughout the day as well. The past four days the water has been clear, but still consuming chlorine at a constant rate. I add 1-1.5 gallons each time I test (~3 times a day). I brush and vaccuum every couple days.

Any advice? Thanks!!!
I’m in the exact same situation and just posted pretty much same. No idea what’s up. I’ll keep an eye on you’re thread and let ya know if I figure my issue out.
 

Fast7

Well-known member
Aug 8, 2018
180
Plainfield, IL
0 CYA and high CC might indicate bacteria turned your CYA int ammonia.
Last test results show low CC, so it looks like you burned thru most of it already.
Keep SLAMing and it should get back to normal soon.
 

jblizzle

Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
43,238
Tucson, AZ
It did show the classic signs of CYA conversion to ammonia, disappearing CYA, high CC, low ph, but pretty rare to occur in such a short time period and with the water not swampy.

Solution is just following the SLAM Process at this point as the ammonia (if that is what it was) is gone now.
 

ntbrink

New member
Aug 5, 2017
3
Indianapolis, IN
At 10:30pm last night, free chlorine measured 13.5.
At 6:30am this morning, it dropped to 10ppm.

Combined chlorine stayed around 0.5.

Just keep at it? I'm consistently adding the same amount of liquid chlorine every day for the past 5-6 days (~4 per day).
 

PoolGate

Gold Supporter
TFP Guide
Jun 7, 2017
4,104
Damascus, MD
Your SLAM criteria is not met (OCLT). Any remaining ammonia (if you ever had it) would immediately consume all of your chlorine. So not ammonia. Sounds like there is just some residual nasties left. Keep at it!