p.s. just got that pH monitor, what a great thing to have TOTAL PEACE OF MIND. I had problems getting a true clear reading from the dropper style test kit since my nutrient recipe makes the resevoir mix brown and almost "muddy" looking (General Hydroponics' Floranova w/ supplements regimen). I'm finding that the ph casually rises up so I start at about 5.6 and allow to rise to 6.2 before I knock it back down. This way I absorb nutrients at different pH levels within the safe zone since they do different things at different ph levels. If I had to be too acidic or too "base", I would choose and recomend too acidic (low pH) in my experience. Before I had the digital pH monitor, I had too high (base) pH and what a bad situation that was!!!! Foam, crud, plant and root matter in the water, slime, film, you name it. The addition of organics like Floraliscious require a little TLC to be kept stable and fresh. If the ph gets too high, the resevoir turns into a "black lagoon" where you'd expect a creature to climb out and eat your face. haha. Anyway, I'm probably not tellin' you what you didn't already know, thanks for your input.