it's the inconsistencies that might get ya from time to time... pH and whatever else someone tossed into it upstream, lol. Any major farms nearby? could be loaded with anything and your eye cannot see such things.
a water test would set your mind at ease.. not sure if that's cost-effective... trial and error with a practice plant may be a better route to go.
pH, concentration and ratios of what you give the plant -- one way or another -- have to be within some nominal range for it all to work well. Whether organice, hydro or whatever, that remains true.