Review on Level Up Your Aquarium: The U.P. Aqua Co2 Indicator Unveiled by Gerald Duncan

Works like I would expect any drop checker to do. I like its more minimalist look and how easy it is to hide in the aquarium without drawing too much attention. I've had no issues with the suction cup not sticking and so far the seal has stayed tight with no leaks. The only thing is that the reagent leaked or dried up before it was delivered to me. This didn't bother me because I already had a vial of reagent that I trusted and wanted to use. But I know that others may rely on the reagent provided with the product. To be honest I didn't even bother to contact the seller about this so I'm not sure if they would send a replacement bottle or not.