Unfortunately the time of year when I need to restrict fertilizer applications to many of my Dendrobiums is fast approaching. The recommendation for some of them is to eventually eliminate fertilizer all together. However I have been using RO, rain, or some other form of pure water with fertlizers added back in. Because using pure water over an extended period of time is not the healthiest choice, how should I approach diluting my fertilizer enough to not inference with the dendrobium blooming? I am just not sure how diluted is diluted enough. I guess I could switch to tap water but I have not had it tested in the new house. I know the TDS are about 250ppm, but I have no idea about the break down. Outside of this information it is well water that runs through a Calcite tank to neutralize the pH.