To use coconut water as organic cannabis fertilizer, first make sure that you have the right growing equipment and supplies. Once you have these, you can begin to dilute 1 cup of coconut water into every 4 cups of water in your hydroponic or organicGrowing system. You can also add a tablespoon of Coco Coir to your mix for extra plant nutrients. Keep Coconut Water Fertiliser Diluted For Best Results: Aerating and watering your plants regularly is important, but watering with diluted fertiliser will help ensure that the nutrients are reaching your plants roots. Wait Three Weeks For Plants To Take In Coconut Water Fertiliser: Because coconut water is an acidic substance, it may take some time for the plants to absorb all of the nutrients. Allow them to grow for three weeks before deciding whether or not to switch back to regular fertiliser.