reagents

looking for hanna copper test. I know eBay has them looking for a fellow hobbyist who might want to just get rid of it and help me get it at a little lower cost. let me know :)

I goofed and ordered two ammonia reagent test kits instead of just one. My tank is pretty much cycled now so I don't think I will be able to use 2 of these up before they expire. For what they cost it isn't really worth the hassle of returning it. I don't know if it is common practice here...

Simple question: How does the Trident determine when to tell me a reagent is empty? Does it just go by a timer based on when I last reset a bottler such as the A? (as in an empty alert is automatic after 4 weeks from reset?) Or, does it actually sense fluid no longer being drawn into the...