Man, I'm really bummed. I've been using a ColorQ Pro 7 for a few months as I put my new pool online and just found out today that it's giving me bogus readings. They may be consistent, but they are waaaaaay off.
It says my PH is 7.3, it's really 8.4 (ouch)
It says my FC is 1, it's really 3.2
It says my CH is 150, it's really 130
It says my ALK is 150, it's really 100
Ironically, the reason I now know this is that I installed a PH probe today (chemlink system), and the initial reading was 8.5. I thought the PH was 7.3, so I figured the probe was DOA. Before I RMA'd it, I got the water tested by the pool store.....and woah...glad I did that.
Amazing that it's so poor. I saw several threads here that recommended the unit (thought peppered with skeptics who I should have listened to).
So now I'm looking for a better test kit...