The test strips should be chlorine dioxide, not chlorine (alone).
Test Strips, Chlorine Dioxide, 0-500ppm, 50 strips/vial
I get mine from Amazon.com in the US. Or from W.W. Grainger - an industrial supply
For tubing, you can use silicone, glass tubing, or HDPE - (high density polyethelyne) My first batch was made with vinyl tubing that did something weird, will admit. The second batch had that strange "burning" - but what it was, more than anything, was gas left over in the tubing at the end of the "make" that hardened into some weird plug, which looked like a burn - CDS is naturally a dark yellow gas - I used that batch completely with no problem. (on myself <G>)
Pam