I left a message for Greg Morin to make the KH ref solution as well as a pH/CO2/KH ref alert like their Ph and Ammonia alert type visual test kits.

Hopefully they will do that.
I have a small 20 gallon I'll try the Cal Labs diffuser on.
I think once you get into the larger sizes, about 200-300gph, the venturis are better idea, so this is useful for small tanks that cannot really use the venturis.



Regards,
Tom Barr