I decided to try the Waterguru after reading of some success with it here by a couple of members last year. I religiously test with my TF-100 kit and found myself testing FC and PH daily to satisfy my OCD. I have been waiting for my FC to drift down after taking up to SLAM levels at opening to see how accurate it is. Today was the day for the first Waterguru test and it was dead on my TF-100. I’m hopeful it remains so and I can relax on busting out my test kit every day. I will keep this thread updated in the coming days and weeks to validate my short lived opinion.