Does anyone know of a commercially available test that will accurately determine CO2 levels in tank water??? I've used the KH vs. PH method, which seems unreliable, and the two agent Red Sea Fresh Lab Deluxe method (maybe I'm color blind, but the shade of the 10ml of tankwater is so pale I can't really tell when it changes from blue green to blue or blue/grey/pink). Does a reliable, accurate test exist (for less than an arm and a leg)? Also, am I to understand that too much CO2 can trigger algae outbreaks? My drop checker stays greenish yellow, my fish don't do any surface breathing, my plants are growing well, but I do have marginal algae issues (some green spot, some BBA). I really want to try to get the CO2 levels right, but without an accurate way to measure I'm not sure I can.