Have you tested for metals in your water? Sounds like you may be trying to get rid of copper or iron with chlorine--which won't work.

The Taylor K-2006 is pretty much the same as the old PS kits. They run $50-$70. Sounds like you need it.

You can test the concentration of the LC, but only if you have the FAS-DPD test for chlorine. You simply add .5cc of LC to 5 liters of tap water (test the tap water first for its FC level), and test it for FC. You're mimicking the concentration of adding 1 gallon of LC to 10,000 gallons of water. The FC level that results (minus the FC level of the tap water) is the approximate concentration of the LC.