I agree on the cheap PH meters- having gone through the same thing. 3 berries is very right in that there is no calcium or other components such as magnesium in it. I hesitated but will offer some info based on science that somehow I expect others to argue. the condensate water from a dehumidifier is distilled and quite corrosive so it absorbs many chemicals and metals and even stuff in the atmosphere like crazy. for example, if left in open air, even the CO2 from the air will lead to the PH dropping (CO2 leads to carbonic acid) in distilled water. I know people do it, but it can easily lead to issues depending on the plants watered and the soils you use. the distilled water can test at one ph and as soon as it gets in with whatever medium, in this case soil, it will effectively drop significantly as things are basically disolved to end up in the water. distilled water is actually quite corrosive and not buffered by "stuff" normally in water so it can change quickly and aggressively. i dont know what the metal from the coil (usually aluminum) will do to cannabis but pretty much guaranteed it will be there. as a side example of it's affect -when used in an aquarium, adding PH 8 distilled water actually can drop the ph of the aquarium by 2 or 3 easily depending on how much of it is added compared to the total volume of the tank.