I have been checking on some filters. I found a Everpure H-300 filter that will remove all but two elements that RO does and will give me all I need at a time. I have one of these systems already in my, house will be getting another one for garage. I PHed the water in res now to 5.45. What is a good rule of thumb to start at with the ppm's? I have no idea what the ppms would be with my current recipe will be nice to know. The tds meter is $129.00 at the hydro store will take me a week or so to get the cash. I'm laid off work so lots of time to garden but not much money to put into it.