Phase I of Project Blackwatch is a wash temperature trial; Phase II evaluates an active comparator - Vitamin C / ascorbic acid as a reducing agent that neutralizes washwater chlorine as supplied by drinking water chlorination with chlorine, chloramine and chlorine dioxide.  These compounds subtly but inexorably remove color from cellulosic textiles.

Textile monitors will be washed and dried the same 26 times as in Phase I, corresponding to six months of wear, at three temperature conditions - tap cold, 86F/30C (aka Care Tag Cold) and 107F/40C (aka Care Tag Warm), but with the addition of a titrated dose of Vitamin C / Ascorbic acid powder to neutralize tap water sanitizer residuals.  I'll be monitoring ORP using my Kismai Æssistant telemetry platform to adjust the Vitamin C dose to create a constant ORP as sanitizer levels ebb and flow in my supply water.

As in Phase I, Colorimetry will be recorded before washing and after washes 1, 2, 3, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24 and 26. 

Reference Photos will also be taken before washing and at washes 1, 4, 8, 12, 16, 20 and 26. 

You'll be able to see the colorimetery and reference photos as they're published, along with videos on my YouTube channel.  In this phase, the final results will be compared to temperature-matched  washed monitors; my hypothesis is that there will be both a colorimetric and visible difference in color intensity at the six month mark thanks to reduced exposure to tap water sanitizer residual.