Hey mate,
Organic fertiliser is as clean as you'll tend to get, apart from brewing up your own nutrients. A few months ago I saw a bloke from the Philippines using his own custom made nutrients and I have never seen a plant act so aggressively and absolutely thrive. I'm talking American super weed quality and this guys only using tap water. He stated beneficial minerals in the water, let's say for example Calcium and Magnesium were still present after adding food.
But please be more specific, what do you mean by "beneficial organisms in the water"? Your beneficial organisms will already be found in cannabis specific soil such as Plagron or BioBizz or they can also be found in top dress mixes.
Watering with bottled nutrients will feed the roots. Watering with top dressed soil will feed the soil and the plant will take what it needs, when it needs.
I hope this has maybe helped you in some way. Feel free to reach out to myself or any other of the members here. We're all happy to help, all the time =)