My questions are:
1. is a 5 gallon bucket of rocks (or whatever) too big for tomato plants? would a 3 gallon bucket be better? would 10 inch netbasket be better yet? Do nets work in E&F systems?

One of the prime benefits of hydro is that the plants need very little root to thrive. If you use a 1 gal bucket and have too many roots, prune the roots. Net baskets are better because it is easy to get to the roots.

2. would an airstone in the bottom of the bucket running 24/7 be of any great benefit?

Yes....dissolved oxygen controls pathogens as well as aerates the roots. Leave it on 24/7.

4. do the roots need to be contained within the top bucket? (not for nets I assume)

Repeat comment about root pruning.

Thanks much. can't wait until spring.

hydro plants will always do better if given more root space. 10" netpots are nice and just slip right on 5 and 2.5 gallon buckets. A 2.5gallon bucket will grow nice sized bushes okay.

It sounds like you want to build something like this:
http://www.hydroponics.net/items/details/multiflow.asp

if you are Id consider buying their controller system bucket. It will make turning the pumps on and off way easier than manually.

Id use a bucket within a bucket over a net pot because of the flooding. I am pretty sure the net pot will not sit low enough in the bucket to be touched by the flooding. With the buckets the root system would stay pretty well contained in there due to the size.

black lava rock makes a nice medium, and its cheap. wash it well before use.

I use a tan colored waterproof Oaktron ph pen, and a cheap Sunleaves tds pen. General Hydro, Dyna, and all the hydro nutrients will get the job done. Advanced Nutrients hydro ferts are what I use, you should check out their www sometime. I use rockwool indoors. 4" cubes on slabs hand watered, very simple but effective.

Im not sure how hot it gets where you are but you'll want to keep resevoir temps below 75 degrees. Also avoid using organic nutrients, that can get some nasty stuff growing.

And lastly dont wait til spring. Go ahead and set up something indoors under floros. Its alot easier to maintain hydro gardens indoors. good luck.

Thanks Hydro_Ken

that system looks great, except it is huge. I might try that after a year of playing around. The controller is the biggest part of it I guess. adding 25 buckets or only 3 isn't much different. probably change my mind 100 more times this week.

I usually see only 10 days/year above 90, rarely above 100 (except last year was hotter than blazes).

Tank temps should be ok because it can be keep in the shade and run the hose to the buckets... that's what I liked about that design.

I'll probably try a few different bucket combos. net pots, double bucket, bubblers, who knows. If thing work out, I'll need more friends to give the tomatoes to.

I'll be ordering a meter in a day or 2. after reading your recomendations. the Dipstick/Digistick caught my eye as well.

I'll try sprouting a few at first. Can't really do indoor because I travel a bunch and don't want hot lamps running while gone.

yes that system is big, but you can design a system from it. I definately think a waterproof ph pen is key, Ive ruined too many that werent. Also you might give 4ft floros a chance indoors, they run very cool and grow nice plants. Indoor hydroponics is perfect for people who travel a bunch... hot lamps are easlly cooled ;) The Land is very cool too btw. later on.

I've heard of poor performance from floros. Anyway, my goal for the first time around is just to see if I can get stuff to grow. I'm going to get a TDS and PH pen. seems like a cheap way to eliminate a big source of problems.

Thanks all, You're the best...

I would build a still water system and add a air stone. I am running 3 of them plus my ebb and flow. E-mail me
chili340@yahoo.com

I haven't read much about the eb/flow systems using the 5 gal buckets but I've heard that there can be headachs getting into the individual buckets to check pH and EC depending on the particular system.
I've done some reading about a bucket set up (and they use net pots) that is essentially a drip system. Not terribly $$ but to automate it there is alittle cost involved. Let me see if I can post the link. The main inovation they are promoting is the drain design that helps keep root intrusion out of the drains. http://www.alabamahydroponics.com/GH/plans/hydropots.htm
For such a system one would need a big resivuar with pump, piping to feed the drippers to the buckets (drippers can be as simple as a hole in the PVC over each bucket,) the drain system from the buckets back to the resivuar, a way to adjust the hight of the buckets and the fall of the drain system, and of course the buckets themselves. This type of system is pretty scallable and you have your choice of media, I've even heard of people using cypress or other wood mulch as media in these systems. Most seem to run the pumps all the time which helps avoid pump burn out apparently.
This system also lends itself well to hooking up a variety of methods within the same system. Say have bato buckets for your tomatoes and a trough running for your squash and perhaps a tower for your strawberries etc. So long as the pump can handle the flow, your resivuar is large enough and you choose plants and nutrients that are happy together then you should be all set. These systems also lend well to float valves that can automatically top up the water in the resivuar as well as automatic dosing of nutrient if you splurge on a controler that can handle those functions. The trick would be to get your system balanced enough that a week absence won't allow the pH to swing too much. This should be doable if you choose your nutrient and media carefully to work well with your water supply and the plants you are growing.
Good luck

Here is a link that might be useful: Hydor Forum