Using Pucks to raise Cyanuric Acid


Jun 30, 2010
What are the Pros and Cons of using my Trichlor pucks to raise my cyanuric acid while changing over to BBB ? Was sold EZ Pool with the pool 6 weeks ago and was never instructed to add any Cyanuric Acid.

I bought a Leslies Total Pool Care DPD test kit - (made by Taylor- alot like their K-2006 except it has R-0001, R-0002, R-0003 for Free, combined, and total Chlorine, instead of the powder like the better kit has.)

Anyway, it does test CYA and my pool tests very, very low still. You can always see the black dot at the bottom of the vial even filled to the top. Water taken to the "pool Man" tests 10 - and he crosses it off the recommended additions on the printout sheet.

Since I still have Trichlor pucks and they raise CYA which I need in order to use BBB anyway--- should I just keep using them for a while longer, although it doesn't seem to be going up very fast. I have added 1 -3" puck per week for 6 weeks now.
OR should I just put them on the shelf and go buy Cyanuric Acid now?

We have gotten ALOT of rain this summer and have had to raise alkalinty several times, last test was
FC 0
TC .5
Alk 62 ( he recommened 1 1/2 lbs Sodium Bicarbonate)
PH 7.2
CH 323 ( he recommend 1 1/2 lbs Calcium Chloride) I think this is because of the parameters EZ Pool needs, 350-500, however, I did not add anymore.
CYA 10

What do you think?

16' AG Vinyl, Hayward Highrate 17" Dreamline Sand filter,
Hayward 1hp Power-flo LX


LifeTime Supporter
May 27, 2008
Jamestown, ND
Ditch the EZ Pool. Its a bunch of junk you dont need. When I first bought my house with the pool, the pool place did a number on me as well. Got rid of it in a yard sale the next summer. Didnt work and added stuff that I never knew was in it6 anyway. Dont need to add any CH. Its a Vinyl pool. Head to Pool School to assist you. I do use Trichlor or Dichlor to help raise my CYA but thats pretty low. A Sock filled with some granular stabalizer which you put over one of the returns is the ticket here. Again, most of this is in Pool School.

Im sure someone will be along soon to offer more/better advice but this will get you started. And oh, you really need to add some bleach to the pool to get your FC up to at least 2 ppm for starters.

Good luck.

Jersey Devil

Platinum Supporter
Aug 4, 2007
Jackson, NJ
I agree that you need some granular CYA added as advised by Reindeerboy. I am winging it, but pucks are around 7 oz. and are about 55% CYA by weight. Therefore each puck adds about .25 lb CYA (give or take) per week. Not sure of your pool volume, but if it's 4 ft. deep its around 6000 gal. or about 41,000 lb., so your pucks are adding about 5-6 ppm per week. All things considered, you should have been there in six weeks. Perhaps you have lost CYA through backwashing, splashing, etc. You need to be in the 30 - 50 range, so use the pool calculator and shoot for a target of 30 ppm. It will take the better part of a week to dissolve and get a meaningful reading. In the meantime, you can use some of your pucks but take care not to allow the CYA much above 50 ppm and be sure to adjust your FC with bleach (much easier to control than tri-chlor) to the level recommended by the Calculator or the chart in Pool School.


TFP Expert
LifeTime Supporter
Feb 23, 2008
Denton, TX
You can chlorinate with the trichlor tablets if you would like to. Sooner or later, your CYA will come up. But I would never let that FC get down to zero like you have. The problem with trichlor tablets is that they are very slow to dissolve. You need some FC in there quickly and I would suggest bleach for that purpose.

If this were my pool, I would store the trichlor though and would proceed to add enough stabilizer to get you to 30 ppm and raise the FC to 4 (don't let it fall below 3). Since you don't have any chlorine to speak of in there, go ahead and use bleach. It's fast and easy.

Once your CYA is at 30, you can determine from that point if you want to raise it more.

Raising your TA up to 80 or so wouldn't be a bad idea. It's not pressing but when TA gets on the too low side, the pH can swing fairly wildly.