The tomatoes, peppers and zucchini all will want a much higher level of nutrients, while the herbs will want a lower strength nutrient. You may need a nutrient with more potassium for the vine crops, but may be able to get away with using the same for both, just at different EC/ppm levels. I am not sure about the onions. I would split into those two groups. Not sure about the light cycle, but would imagine they both would do fine with 18 light - 6 dark or something close.
I would make sure to prune your tomatoes and peppers to limit both the size and number of fruit otherwise you will end up with a tangled mess and small underdeveloped fruit. Those plants can get big quick and crowd other plants.
My first year growing in a mini rooftop greenhouse I had 12 plants... I quickly learned the lesson above and only planted 6 plants in the same space the following year.

I am a new member too, but have 10 years of successful hydroponics. Tomatoes,cucs,broccoli. I use natural light and have figured how to grow outdoors without nute dilution. I have also refined my systems to be inexpensive, reliable, and expandable. I am a designer/ inventor by trade and developed and most of my own components. I use DWC as my mature growth platform. I start plants in vermiculite, then transplant to flood and drain till the roots hang low. They then finish in DWC system. Never had much for problems.

Check each of your plants photoperiod. You could use one room to start your peppers and tomatoes off then move them to the next room with an HPS light for a all year continual veggie harvest. I grow a cherry tomatoe inside in a DWC under a 150w hps.I start another couple in another area so when the one is finally done producing tomatoes I bring in a new one this way im allways harvesting.

My input is grow outdoors. Why do all the artificial light stuff. If you are not growing illegal plants, bring it outside. The natural light period has worked for all plants over the millennium. The next point is why add more cost to your fruit with more electricity from lights. You are already got the cost of timers and pumps. It is all about sustainability. I like the idea of solar energy to run the system. It can be done. I've done it. 12V timers, aerators and bilge pumps.

Timerguy,

Wow! Thanks for all the input. As far as pruning the tomatoes, I did see a video where they were showing how to pinch off growth in the crotches of the vine, but strangely I don't see that on my plants.
I grow indoors because I want to avoid pests...bugs and small mammals, and also because I plan to do this over the winter.
The red bell peppers are starting to flower. They're in the same room with the tomatoes.
The herbs are in a different room with a different light source.
Still no flowers on my tomatoes, but I'll try and be patient. I did increase the bloom solution at last water change, so I'm hoping that will help.
"The Master Gardener"...thanks...this is very helpful. My garden started out like that by accident, since I added the other room as an afterthought. The older plants were started in the smaller room with a 200w light and then when I expanded they ended up in the new area with a 400w light source.
"sdgrower"...thank much! I have a mild solution for the herb ebb & flo system, and a more specific solution for the peppers (ebb & flo) and tomatoes(buckets).
The onions seem to like that milder solution, as do the zucchini (which is growing huge BTW)...
I posted a video showing my little operation on my webpage:
www.brucesblues.com
It's in the newsletter section....just scroll down a bit.
Thanks for all the help!
astrumur

Yea pruning tomatoes can be tricky at first. Any new branch off a main branch is a sucker and you need to cut it out. Well I am glad our info has helped.
Good luck.

Looks like the tomatoes are starting to flower now...I see small little buds appearing!
Here's a question: Does it make sense for the small hydro gardener to mix up one's own nutrients? It's gotta be cheaper. These nutrients are expensive!
Many Thanks!
Bruce