Using trichlor pucks in an old 20k gal vinyl pool

[jmshivley]

Hey all. Purchased a home last year with a 20,000 gallon pool with a dilapidated pump/filter and really old vinyl liner (all 10+ years). Had serious problems the 2 months it as opened with pool chemistry, leaking, problematic equipment, and algae...so much so I was just about ready to give up on the pool. I've been reading posts in this forum for the past year and it has helped tremendously. I am now currently employing the BBB method. Recently had my sand filter and pump replaced/upgraded to a Pentair Tagelus and high performance pump. Also had the auto chlorinator and timer replaced with pentair products as well. Keeping the old vinyl liner for now and just patched about 5 holes in it. It was leaking so bad. The pool has been a joy to use and maintain since the upgrades and BBB method. I do still use the automatic inline chlorinator with 3" pucks. I know these have CYA in them and have also read that they affect the pH. Please give me the low down on these pucks...

[PoolDoc]

What you heard is correct; trichlor pucks are acidic, and they add about 6 ppm of CYA for every 10 ppm of chlorine.

So . . . you need a K2006 testkit in order to manage your chlorine and CYA. The reason is, the proper chlorine level is determined by the CYA level. In most cases your chlorine level needs to be about 10% of your CYA level. If everything is perfect, you can go lower, but keep in mind that a single algae episode can consume a month's worth of chemicals.

Read http://pool9.net/cl-cya to understand the Cl - CYA relationship.

Read http://pool9.net/tk for kit info.

Test strips are too inaccurate to be an option, even when read by computer. The CYA test, in particular, is horrendously inaccurate.