Raise CYA with Trichlor Tabs?

[Michael1]

My CYA started out at 150 when I got my house with the pool. With water changes, using the TFP methods here, and general degradation of CYA, it is now under 20. So I need to raise it a bit. I was thinking of using a floater with Trichlor to do this. I am going on vacation this summer, and will have to use a floater to keep the chlorine up. I thought this would be a good time to "practice" with it while I can keep a close eye on things. Since my pool gets a lot of wind, my pH is always on the rise, so no worries there.

What should I look for on the Trichlor packaging to be sure I'm not putting a lot of other "junk" in the pool? I guess I've gotten a bit anal and protective of my clean water after doing the TFP method.

 

[woodyp]

Pucks is pucks!

 

[Michael1]

Pucks is pucks!

Not so sure after reading this.

"ARRGGHHH!!!! Reading the label today, I see they have other junk in them besides stabilizer. They are trichlor but seem to have 3.5% zinc sulfate monohydrate and 5.4% "other" plus the label says "ULTRA - contains built-in algae fighter, built-in resistance to sunlight, built-in clarifier, contains stain and scale preventer, softens water""

https://www.troublefreepool.com/threads/67273-leaving-new-pool-for-3-weeks-tab-question?highlight=tabs+raise

 

[Michael1]

I did some research on this, and ended up buying Chlorox Active 99 tabs at Lowes. They are 99% Trichlor. Others are not, including the Chlorox XtraBlue line of products, and all the Pool Time products I saw at Home Depot. I would think a Trouble Free Pool person would be interested in the Trichlor products without all the extra chemicals.

You can see the MSDS for Chlorox XtraBlue. It says "Trade Secret" 3 - 8%. Who knows what that is. I don't think I want it in my water whatever that is.

Chlorox XtraBlue MSDS

I am using them to raise my CYA, which right now is at 10, and I am going through bleach like it is going out of style. I will switch to back to bleach once my CYA hits 30. That will give me a cushion when I need to use them while on vacation.

I also used the Poolmath calculator on this site to figure out how may tabs I needed to bring up my CYA to the point. I will continue to test the pH, chlorine, and CYA during the time I am using the tabs. Trichlor tabs will lower your pH, but my pool uses a lot of acid with all the wind it gets, so I should be OK. Based on my calculations, my CYA should go up 1.2 per day. We'll see. It becomes readily apparent why you can't use chlorine tabs on a continual basis. The CYA will go to the moon.