Everyone over the years develops their own favorite water lily dirt recipe. But I was reading an old ACRES publication (it's a mag about farming) about farmer's efforts to add back minerals to depleted soils to improve the nutritional qualities of vegetables, pastures, etc. There is a lot more to fertilizer than nitrogen, potassium, and potash.
Many of the more expensive aquatic fertilizers have micronutrients that try and mimic the natural mineral content of "not depleted" soils.
Magnesium, calcium, halite (sodium chloride), sulphur, iron, phosphorus, manganese, iodine, zinc, etc are only some of the minerals that exist in soils and salts.
Minerals come from broken down rocks. So I was thinking that maybe adding a cheap bag of gravel to my water lily soil recipe. What do you think? When I wash a bag of gravel, all of the gunk that washes away is actually the broken down minerals from the rocks. I was treating it as a waste product and washing it away instead of recognizing the value of it.
I was also thinking about adding a few bags to my vegetable garden.