Tomato Disease?
 

I just started my hydro tomatoes in early November. A month after seed germination they are quite tall and very full. I have noticed some discoloration on them. There is also curling of the leaves but that is probably an over-watering issue.

The discoloration is yellow and is spotty at times. There are also portions of the leaves dying, turning brown but not falling off. I am picking them off with my fingers. I have cut entire branches off the lower portions because the entire branch of leaves is brown (note, the actual branch appears healthy - only the leaves die). I'd rather not destroy a month and a half of work due to a disease, especially if I can fix it. Any help is greatly appreciated!

While my issues weren't quite as extreme as what you appear to be describing, I too posted here about some issues I had with my tomato plants. I believe in my particular case a large part of my problem was nutrient related. My leaves didn't curl upwards however, mine were just sort of "droopy" and wilted looking. What you are experiencing, however, could potentially be anything from growing conditions to nutrients to leaf curl virus.

I'm no expert on this by any means, but it would probably be of more benefit if you could describe your growing conditions/process in a little more detail so the folks here could try to help narrow down the problem area. What type of system are you growing in, light types/setup, what is your watering cycle, type of nutrients you're using, pH of the nutrient solution, temp of the nutrient solution, strength of the solution (ppm/ec, etc), what the roots look like (white vs. brown, etc). As many of these details as you can provide could potentially help isolate what could be causing the issue.

Tomato's are very susceptible to many things, disease, pests, viruses. Any and all information mentioned above will help narrow things down, the more information the better. Also, have you seen any pests/bugs on the plants at all, if so take pictures if you can. Pests can transmit viruses to the plants. There's no point to starting over if the new plants get the same pests. In the search for finding an answer to my tomato plant problems I found a page that might help you identify your symptoms.

Tomato Disease Identification Key

My issues have multiple factors but seem to steam from the virus transmitted from a pest called a "winged pea or potato aphid" (pictures attached). You don't seem to have the same symptoms with your tomato's by your pictures. If you are growing inside don't be quick to dismiss pests, they can easily make there way inside greenhouses and your home. They also can be harder to get rid of inside.