Get a 400w reflectorized HPS lamp from HTG supply, and a regular cheap 129$ 400w hps ballast from the same place. The lamp has its own reflector, and studies of plant lumens show that HPS has them all beat. If you're looking for a lamp to make your plants look pretty, then you have to buy a reflector and run a GE CMH lamp that runs on the same HPS ballast. The lamp has a white light that looks like the sun - it will cure you if you have seasonal affective disorder, and u will save a lot of money on antidepressants. Your plants will also grow quite well. Pulse start metal halide is also a good lamp, Ushio makes some really nice lamps, but the ballast is a little harder to find, it has to be pulse start (not probe start). Sativa.

Here is a link that might be useful: A good read for anyone browsing thru this forum, or ever wanted to know something about everything.

Sativa,

Thanks so much for the help. Do you think that one of these is enough? (or that 400w is enough)

How large an area in the sunroom will you need to cover with the plant light? What directions do the windows face, and it is sunny or are the windows shaded by buildings, trees, etc. What kind of high and low temperatures will your room have?

You will need to watch carefully for pests, especially spider mites. I used to try to overwinter tropicals like ee, passiflora and tropical hibiscus as houseplants, but the pests always became a huge issue. Now I have much better luck overwintering them in a cool, dim room (think basement) with minimal watering until spring. They don't grow, but it's cool enough that the pests stay fairly dormant too.

It's not as pretty or as fun, but it is WAY less work, plus the plants are much healthier when they go back outside in the spring. They used to need all summer just to recover from the pest damage before they could grow and bloom.

But I still lust for an indoor tropical room or greenhouse. Maybe someday when I win the lottery.

I think a 400w reflectorized HPS would be fine for a 4 x 6' area. If it's bigger, go for the 600w reflectorized HPS, with 95,000 lumens for a 5 x 10' area, that's about 2,000 lumens per square foot, and HPS lumens score very high with plant lumens. Get your setup from HTG supply, they are the cheapest, and not many outfits supply the generic reflectorized, which in my grow room works like a charm. Sativa.

Cool, Sativa. Thanks! I know that you and Lermer were discussing CMH bulbs...do you think that those are a good option, or should i just stick with HPS?

I'll provide you a very useful link that you can read and decide for yourself. The deal maker for me, is that the HTG reflectorized HPS lamp is MAGNIFICENT because the reflector is an integral part of the lamp, it has been designed by an optical engineer, and it means that the lumens ALL GO DOWN on your plants in a nice even blanket. Now CMH, I also like CMH lamps because of their beautiful spectrum, which is important in the early stages of plant growth, much more important in the baby seedling immature stage than the grown up stage. Think of CMH being like mother's milk, very nutritious and complete, is does everything for the baby. Once the baby has grown up, he can live on Macaroni and Cheese, or baked beans on toast, for the rest of his life, and still be healthy enough, even put on weight and be reasonably strong. CMH requires an external reflector, which adds cost, and there is no reflector that I have seen that is as good as the reflectorized (Gavita type) lamp. Also, you may even have a bit of natural light to supplement the artificial light, which is a bonus.

My answer, based on the science, is that HPS is better, because you get more "plant lumens" per watt, and that you can buy it with a built in reflector. The build in reflector is what makes the deal for me. If you wish to buy a reflector, and it has the right pattern for the shape of your garden, then your plants should grow quite well with CMH. CMH runs on the same magnetic (non-electronic) ballast as HPS, so if you need to budget, buy the HPS lamp this year, and the CMH next year. However, if you need a 600w lamp, then you can only use HPS because CMH does not come in 600w size.
Just read the following link, which is an actual scientific, non-commercial, paper about how light and plants work.
I'll just add, early plant growth needs more blue, to keep the plant in the correct shape; without blue, it will get lanky, and plants need blue light to synthesize chlorophyll.
Because you are dealing with mature plants, then the following link will apply:

Here is a link that might be useful: The real goods on Photosynthesis Action Spectrum, and how to scientifically compare on lamp with another, and does spectrum really matter.

Sativa,

Thank you so much for your help! I finally got off my butt and measured the room...almost 12 x 8....should i get two lights, (one being a hps and one a CMH) or a 600w? I just don't want overkill. I also wonder how negligble the light difference is between white paint and mylar. For prettyness sake i may go with the flat white.

600w for sure, browse thru HTG supply for the ballast and reflectorized HPS lamp. Start with one lamp. Use flat white paint, it works well, and after a season, reassess. I'm sure you will be satisfied, and if not, get a second 600w hps. :)
the heat from the lamps will help keep your house warm in the winter. Sativa.

Sativa,

Thanks for all your help...this newbie really appreciates it....

what do you think of this kit?

or should i just pick and choose?

Here is a link that might be useful: HTG digital kit for dummies

It looks nice, and it's cheap enough too, which satisfies both my requirements. HTG has been in business for a long time, I buy from them, and I've always been satisfied. I have no idea about the susceptibility of these items to line volt surges, but on the other hand, I haven't heard any complaints about this either, it may even have it's own built in inherent protection. Personally, I've never had any blown equipment due to surges, and electronic ballasts are extremely common in the home, so it looks like a wise purchase. Sativa.