Definitely worth it if you can afford it. There is nothing like a full spectrum bulb for plant growth. The color life of the bulb is about a year to a year and a half. The bulb will last longer than that, two to four years, but the color spectrum will start to fade after about a year. Even though the color fades, you can still grow good plants with it.

It would be for supplementing in a greenhouse but only from Nov - Mar, so it would last twice as long, since it would only be used half as much.

Some say straight HPS is OK, and I might go that route as the Super Blue is VERY expensive, but I might try an experiment, one straight HPS and one straight Super Blue.

I wish Ceramic MH came in 1000W...

I'll be shutting my GH down from mid-Dec to mid-Feb except for the front 1/3. Simply not enough sunlight to "grow" anything economically, though I can overwinter bananas and such there fairly cheaply.

Mike

Where do you live, wordwiz?

I'm in Maryland, Baltimore area. Our winter sunshine is hit-or-miss, much better than my native Ohio, but not as good as many other areas. We still have more cloud cover than I'd prefer, though.

The land of the Reds and Bengals - Cincy. From about the middle of December to a week ago, I could count the number of hours sunlight hit my greenhouse on my fingers and toes - and have my thumbs and big toes go unused! In the last ten days or so, it has picked up. The sun is high enough on the horizon that when it is shining, the GH gets the light until close to 5 PM. A month ago, at 4:i5 it was in shadows. At 6 this evening, it was still 83.5F in it, though by 7 it was 63! That is with no supplemental heat.

I have room upstairs where I can realistically grow 50 or more tomato plants, without having to provide any heat (ambient excluded!). I'm experimenting now to see if I can use 75 watts of HPS per hour for 16 hours a day per plant to get a good harvest.

Mike

What size and material is your GH?

See this thread.

Mike

Some say straight HPS is OK, and I might go that route as the Super Blue is VERY expensive, but I might try an experiment, one straight HPS and one straight Super Blue.

I wish Ceramic MH came in 1000W...

For experimental purposes, you should get Eye Blue (not Eye Super Blue) MH. Otherwise, you are not separating variables, i.e., the HPS in the HPS from the HPS in the Super Blue dual bulb.

Why not use 400 watts of each?