http://www.aquaticplantcentral.com/foru ... agram.html
Newbie that I am, I'm not sure if it's 100% accurate, but I found it informative. I've gotten to the point where I can fairly easily recognize and address potassium deficiency (pinholes, sometimes with yellowing), but beyond that, perhaps I haven't had other nutrient deficiencies, because I haven't seen these other symptoms. Then again, I've always used "nutrient rich" substrates like ecocomplete or flourite, so maybe that's why. Oh, and liquid rock for tap water probably helps.
