Review on 🧪 Convenient Essential 2210 Plastic Hydrion Dispenser for Hassle-free Testing by Mario Schultz

This product has been shown to be useful and is at least one year past its expiration date when received. In the short useful pH range of 5.0-7.0, as far as I can tell, there are no visually highly contrasting indicator dyes or mixtures in this application. So it is not surprising that this (#2210) and a similar near pH range of 4.5-7.5 (#334) are calibrated in increments of 0.5 units. (#067 5.5-8.0 has a shorter pitch color chart (not evenly spaced) but it is useless as pH values below 5.7 cannot be distinguished from one another.) The manufacturer may have recommendations, however I found that the eye can be helped by paying attention to lighting. For example, in a room with household lightbulbs designed to enhance certain pleasant tones, the ambient lighting made reading really difficult—unless supplemented by another type of lamp. This is for better assimilation of specific components by roots in a specific environment. (And coincidentally or not, this year's tomatoes actually turned out really well.)