Cloudy & Can't Hold Chlorine


New member
Jul 30, 2007
TC 1.5
CC 1.5
PH 6.9
CYA 80
Alkaliity 142
Hardness 349

Inground, vinyl, 23,000 gallons, Pump runs 7 X 24 .... 3 pucks in the two skimmers

Super shocked (21 lbs) 8 days ago and held for 24 hours .... super shocked (21 lb) the next day and held chlorine over 10 PMM for 24+ hours

A few days after shock chlorine goes to zero even with 3 3" pucks in each skimmer and pump runs 7 x 24

Pool now cloudy, barely see drain '8 ft down, and algae on floor.

What is happening

I just raised the PH and hit it again with 4 gallons of liquid chlorine


TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
Silver Spring, MD
Welcome to TFP!

With a CYA level of 80 you need to bring your FC level up to 20 and hold it there to kill all the algae growing in your pool. Shocking to lower levels might knock it down a bit but it is unlikely to kill everything off.

As your CYA gets higher you need to use higher and higher FC levels to prevent algae. Using pucks is adding even more CYA. You are already as high as it is a good idea to go with CYA. At the current rate you will soon be well above that. I suggest you switch to liquid chlorine/bleach as your only chlorine source. It won't add any more CYA.


New member
Jul 30, 2007
thanks for you reply. I was thinking the same thing but pool store did not think so. I went to another pool store to get liquid chlorine. I am going to switch to liquid chlorine, and do my own testing. What is a good test kit for FC, TC, PH, and CYA?

The Mermaid Queen

TFP Expert
LifeTime Supporter
Mar 28, 2007
Northern KY
check out my sig for a great test kit. There are other good ones available, but not put together with the same amount of thought and support you will get from Dave. Reagents are in sized that are useful, and the instructions are quite clear. Any questions you have, Dave (and others who know their stuff) is here to solve all your woes!

Moved to "Testing the Water" by TMQ 7/31/07


Well-known member
Jul 15, 2007
I have a similar size pool, 22k gal. Get the regular chlorine jugs from the pool store (2.5gal sodium hypochlorite, 10-12% strength). And stop using any kind of pucks, they contain CYA.

A chemical chart I have says 1gal of 12% will raise 12,000gal to 10ppm. Pouring two jugs in my pool raises FC to about 25ppm.

99% of the time, don't bother listening to pool stores. With the exception of the owners/managers, most of them are part-time students. No offense to anyone.... just the facts... at least in my area.