How To Use Progressive Web App aka PWA On 420 Magazine Forum
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I pasted your question in Google, lots of options for you, most evap. it, not much on feeding it to plants.
I would not use the 450ish ppm water for hydrating your coco coir. 450ish ppm without any calcium and magnesium in it would only add more ppm to your grow medium.
What I am suggesting is 450 ppm without any calcium and magnesium in it yet may that will be necessary may be too high of ppm for whatever plant you wish to place in the medium.