Quote Originally Posted by BillyBumbler
I have an 18000 gal. IG pool/spa combo that has been running a week. Until I a m allowed to start my SWC in a couple months, my basic plan on the Chlorine front was to keep a couple of 3" pucks in a floater and add a gallon of 12% chlorine once a week to shock. According to the bleach calc (nice little tool!), a gallon of 12% would be just right for shocking purposes. However no where can I find a formula for how many trichlor tabs to use at once. The avg. water temp is right around 85 degrees. So far my Ph is holding steady at 7.6, though I believe I am right on the edge of going to 7.8. TA is always 90. Is it too early to worry about Calcium hardness and TDS? Until I get my new kit I won't know how much CYA the pool guy added at start up. Thanks!
Don't worry about TDS, and only worry about calcium hardness if you have a concrete/plaster pool. If it's vinyl lined, don't worry about it at all.

As far as the puck usage goes, if your pool guy didn't add any CYA at startup, then the pucks are okay for now, provided you don't let your pH drop too low--they are very acidic and tend to pull your pH down. However, if your CYA is already at what your SWG needs, then I'd stop the pucks and just use the bleach.

Shocking with 12% is fine. As Sherra pointed out, shocking is really not necessary unless you have a CC reading or your water starts to look cloudy, but I do shock mine more often just to head off any problems before they get a chance to happen!

Janet