When did they start using trichlor for shock?

[markayash]

I had a slight yellow algea bloom creeping in and knew my calcium was a little low so went to walmart to but a few bags of shock. Luckily, after learning from here, i checked the ingredients and the cheap stuff wasnt calcuim based but the expensive HTH was which is what i bought Use to be all Shock was the same but not anymore. No wonder everybody has a CYA issue

 

[kimkats]

It is either CYA or CH.............both needed for a plaster pool but too much and it is not good...............You did the best thing by reading to see what is in it!!! Plus watch for anything that says BLUE......it almost always has copper in it

 

[markayash]

My CYA is around 80 after i dropped it 18” and refilled so dont want that for sure.
It said 4 in 1 but wasnt blue so think it was marketing stuff.

 

[kimkats]

They will try anyway to get a buyers attention that is for sure! I am SO glad you know the difference and what to look for. With your CYA of 80 you are smart to not add any more. There are so many pool owners that just do not have a clue