Calcium is quite important to a tomato plant, but one does not
really see much in the way of deficiency symptoms until fruit
start to develop (blossom end rot). Looking at your formulation
at the bottom, I might want a little more iron, but the leaves
are not showing iron deficiency symptoms, so I guess it is ok
in the context of the levels of the other nutrients there.
(I have seen obvious iron deficiency symptoms on plants
growing in soils with more iron than what your fertilizer
supplies but a lot higher zinc levels, too.)
Some kind of mineral salt not in any of the ingredient lists
that builds up in the solution, maybe?
The page below indexes documentation on a lot of different
kinds of "plant stress", including mineral toxicities, toxic
salt buildup, etc:
http://www.plantstress.com/Articles/index.asp