Should be a sticky if accurate! The diagram was great, but it's always nice to see an actual color "picture" too, especially for slow learners like me!
I think it would be better if there was a line across the picture that divides old and new growth simply for ease of finding old growth and new growth problems.
Also, the calcium twisted tip leaf looks like a normal leaf? I'm not sure if there is a twisted leaf in front of a normal leaf since the picture gets a bit grainy when I zoom in.
zapins,
from a graphic design perspective, i chose to not use the line to keep the illustration as simple as possible. I had the line before and removed it as it was drawing too much attention in the diagram. The visual space itself would be the distinguishing factor as the supporting text somewhat creates these 2 sections.
With the twisted leaf you are right, I was looking to mimic one but couldn't get the right effect. I'll continue to search for one and edit it in the coming days.
I think with or without a line (to define old growth versus new), this really needs to be a sticky. Can't urge that enough. Having a visual diagram like this, with explanations, is excellent.
Could a Moderator please indicate what is preventing this from becoming a sticky, so it can be fixed? The original posts have been great, but a diagram that is more dimensional with color like this is so much better, especially for noobs to the hobby!
I agree that this is one worth being 'stuck'. I am going to print it on my color printer and hang it up by my tanks for quick reference. It would be especially useful for those just getting into planted tanks.
Here is a table that I saved from Aquatic Gardener 1993. It would be nicer if there is a color foto next to each symptom. Feel free to incorporate it into your diagram, or put a picture next to the symptom in the table.
Plant Deficiency Diagram 
It really helped me out when I first saw it.
Linear Mode
