You can't buy chlorine on line but you can buy CYA. Curiously, Leslie's on-line service is a heckuva lot better than their in-store service, which is very, very spotty. On-line is very reliable and I've never had a problem with it. On-Line is the only place to get their FAS-DPD Chlorine Service Test Kit (Equiv to the Taylor K2006 or Ben's PS-232, 233, 234, or the TFP kit) Some stores are better than others. The BEST pool store in my area is Sun Pools in Green Brook, NJ--near my office but not near my house. They really know their stuff and don't push nearly as much as other stores. I'd rather pay them a bit more for their carboys because it's ALWAYS fresh and frequently tests as high as 14%. The best pool store near me is Rix, in East Hanover, NJ, but they push BioGarbage at Boo-Coo bucks. Still, their filter sand and DE prices are very good, and their ability to have JUST the fitting I need on a Saturday or Sunday is terrific, so I'll give them business as well.

Again, you CAN use Tri-Chlor tabs but you must test your water weekly (not weakly ) and STOP if CYA goes too high are pH keeps going too low.