Join Date: Jul 2010
Location: Outside Philadelphia, PA
A 250W MH would be considered very high intensity, especially right under the bulb. For awhile I used two 150W HQI bulbs on my 90 gal planted tank, and that was way too much.
I also found a couple of other things with MH on planted thanks. They are point light sources, so you do get that real nice shimmer, but you also get dark shadows. Sometimes it's hard to get light way down into dense plants because of the shadows.
Also, most SW people are using bulbs in the higher color temp range, about 15000K to 20000K. While great for a SW reef, bulbs like this tend to make a FW planted tank look very unnatural. If your going to go with MHs, consider getting a bulb in the range of 6500K to about 10000K. I found 6500K bulbs looked very yellow. This might be good if you wanted the look of that sunlit pool in the woods, but I liked the ones around 10000K.
All that being said, you might want to consider getting T5 lighting. It's not that expensive, and will be a lot more even across the tank. You could start with a 2 bulb fixture, and for most applications that would be plenty. It would also be a lot less expensive to run, and throw off a lot less heat compared to MH. If you later wanted to go very high tech, you could then add another 2 bulb T5 fixture over the tank.