Gotcha.
I have another question for you about TDS meters. Not sure if you work with one, however, I just bought one pretty cheaply off ebay and just measured the water in my reservior which is reading 415 ppm. Im trying to follow the BCNL grow guide to a tee and their recipe calls for a MAX ppm of 210 for week one. However, my tap water itself is 150 ppm. My question is, when BCNL calls for a 210 ppm reservior with nutrients, do I need to account for the base ppms in my normal tap water? How to I accurately meet the recipe calling for 210 ppm?