Now THAT's what I call a terrarium!

The bulb is a little pricy and a little short-lived. Is there something in particular you want that this bulb provides? 6500K? CRI 90? If not, you can get more lumens, twice the bulb life, and for less money.

Also, will your existing ballast drive this bulb efficiently?

My existing ballast won't drive it at all. I'll be getting a new ballast as well. I'll probably use the 400 in the winter and the 250 in the summer. I wanted it for everything really, it has a great CRI, a great color temp, and still nearly twice the lumens of my 250 watt. Some say CRI is all that counts, some say lumens, some say color temp. This bulb has all of them :) I figured it was easier than trying to sort out fact from fiction.

-DH

If CRI was all that counted, I'd be growing my cactus collection under a 40W incandescent :)

I guess the price isn't too important when you'll use $500 or more of electricity over the lifetime of the bulb.

Now, I did a bit of research into the bulb specs. Every MT400DL/BH bulb I can find actually has 29,000 initial lumens, so I suspect they are scamming you a bit with the 36,000. Now maybe they found a new manufacturer that can churn out better bulbs than Iwasaki and Hortilux for a lower price, but I'm guessing not :)

The bulbs for vertical mounting come in at 32,000 initiual lumens but that might not be any good for your setup. Your price seems to be about as good as you'll find for a single bulb of this type.

If I grew mine under incadescent, I don't know which would have happened first. Bankruptcy from electric bills or a raging inferno :)

Of course CRI isn't all that counts, I'm inclined to think its more lumens than anything. Although I want a color temp that doesn't make my plants look awful too. If you have a better suggestion, I'm all ears. I just need something to get my plants through a michigan winter. I don't pretend to be a light expert. That terrarium is in a sun room and directly under a skylight, so it relies a bit on natural light in the summer. Plus the higher wattage bulb will help keep the terrarium a bit warmer. The sunroom isn't heated.

-DH

I think the bulb will do fine if you get a matching ballast.

I don't know if you've ever tried 6500K lamps with a lower CRI? They make things look pretty grey to me but some people don't notice it.

Nope, never tried it. I'm using a 5000k 65CRI 250 watt right now, and I think it looks great. Of course, I don't have anything to compare it to really. I think I will give this bulb a shot, and if I don't see a difference then I can always replace it with a cheaper bulb when it burns out.

-DH

Try the 400w Philips ceramic metal halide. If you want your plants to look as natural as possible, this bulb has a cri of 85 w/ good lumen output and color temp. It's a white light that runs off a hps ballast.

Yeah I saw that one, and it appears the one I posted above runs on a mercury ballast. Why do all the good MH bulbs use non MH ballasts?

-DH

In the case of Philips and GE they designed a bulb that would run off a HPS ballast to make it easier, less expensive for the consumer to transition from yellow HPS to a more natural/whiter light. I can tell you that you'll love the cmh bulb. Has great properties and your plants will love it to...Find a hydro store near by and check it out.

Good growing.

Its a shame really since most HPS ballasts are rather inefficient lumps of iron :)

I am sure its a great bulb, but I didn't want to buy an hps ballast for it. I guess I will have to stick with my MH for now.

-DH

> Now maybe they found a new manufacturer that can churn out better
> bulbs than Iwasaki and Hortilux for a lower price, but I'm guessing not :)

The original link to the bulb in question indicates that it is from Eye, which is a subsidiary of Iwasaki. (The wording is also compatible with a generic bulb with similar specks to the Iwasaki product.)

It is for a Mercury Vapor ballast, but I've read on aquarium forums that it will work fine on a conventional CWA probe start ballast (M59). A very similar (or identical) bulb, from the same manufacturer is the "Eye Hortilux Blue" available from hydroponic stores, and the "Iwasaki 6500K" from aquarium suppliers.