How rapidly does CYA build up


LifeTime Supporter
May 27, 2007
Fayetteville, Arkansas
Just refilled a 30,000 in ground vinyl pool and the CYA is very low. I'm using 3 Tri pucks in the two skimmers till the CYA level is where I need it to be then I'll switch over to Di pucks.
I don't want to necessarily add extra CYA till I see how fast the pucks bring the proper level up to standards.



Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
Sebring, Florida
Hmmmm. You're gonna' have to go thru a lot of pucks......and I mean a lot of pucks.

I'm doing this from memory so bear with me. I think I used about 20 lbs of CYA to get my 43k pool up around 30ppm. I'm sure my math is wrong but it's close enough for this discussion. So you'd need somewhere around 15 lbs for your 30k pool.

If tri-chlor tabs are 75% available Cl (or thereabouts) then somehwere around 20% is CYA.

That leads me to think your gonna' need to dissolve about 75 lbs of tri-chlor pucks to get to 30ppm.

I'm sorry my calcs are based on such a fuzzy memory but I'm not off by a ton. In short, you're gonna have to get some CYA in there other than thru pucks.


First a queston, what are di pucks? Dichlor is a fast dissolving granular chlorine and does not come in pucks.. Pucks are trichlor. (Cal hypo comes in capsules or tablets, not really pucks. They won't add any CYA.)

Dichlor will raise your CYA faster than trichlor. For every 1 ppm of free chlorine added dichlor will add .9 ppm CYA and triclor will add .6 ppm CYA.