Super high CC with clear water?!?!


Apr 23, 2014
Fort Worth, TX
Hi everyone

New homeowner with a new plaster inground pool (pool is ~4 months old). I had previously been a member of TFT and pool owner several years ago, but now have a new setup...
House is in Fort Worth TX
Have the TF-100 testing kit
Pool - 17000 gallon plaster
Hayward pump with chlorine system
Retractable cover

Yesterday when I opened the pool cover, I noticed the water was a little cloudy, so I tested it...
pH 7.2
FC 0.5
CC 10 (!)
TA 140
CH 400
CYA 40

I went to TFT pool school and read up on SLAMing the pool. Unfortunately, I didn't have any bleach available so I went to the store. Because of Covid, bleach is hard to come by, but Costco had this available...

I'm sure it's not as good as having "true" bleach to use, but I was stuck and didn't have any options.

Sooooo, anyway I added this to the pool per their directions, ran the pump overnight, and Voila(!) the water was clear this morning. So I tested my water thinking everything would be good, but wow was I wrong...
pH 7.5
FC 19
CC 23 (!!!)
TA 130
CYA 65

So I've done a great job of getting the FC up to SLAM levels but I don't understand how my CCs doubled. Like I said, the water is clear and looks great.

I'm very new to this, and would value any thoughts! I appreciate any help in advance!

Lastly, at what level of FC and CC would you consider being "safe" to swim in again?


TFP Expert
LifeTime Supporter
Jun 12, 2009
NW Ohio
Copper AND dichlor. It's not that it isn't "as good", you literally cannot bring a pool to SLAM level with dichlor because your CYA will go up by 36%, thus raising your required SLAM level.