Using a 600w Bulb with a 1000w Ballast?

[S4v]

Sup everybody. Long ago, a friend of mines ordered 4 1000w mh bulbs and ballasts. After about a couple weeks he noticed an area where the growth was smaller than the others and he assumed it was just stunted growth for that plant. He finally noticed the light was a little dimmer and took a look - it was a 400w mh :shocked: Of course he returned the bulb and got the mh that he paid for but my question is: What are the negative effects of using bulbs with lower wattage than the ballast they're powered by? If there are any...

[knna]

HID bulbs are very sensitive to inner tube temp. When running a bulb in a higher watage ballast, it works over its specifications, and run hotter. In the first 100h, it give more light output than nominal, but after that, the output degrades quickly. In less of 1000h, the bulb is burned (although it lit, but less of 60% initial, not cost effective).

Appart from the fact that you are paying near the energy of 1000w and getting only the light of a 400 or 600w bulb (at first, a little more, then less).

The ballast run hotter, too, and it can decrease it life. Your friend must returned both the ballast and the bulb.

knna

[hydrorascal]

Ballasts are wattage rated for a whole bunch of good reasons. Bulbs are matched to the ballast setup to match that whole bunch of good reasons.

A couple of good reasons to match bulbs with ballasts are :
Fire
Fire
Fire
Bulb explosions
Bulb explosions
Bulb explosions

270's in a 250w / 430's in a 400w are even technically pushing it although many do it with no ill effects.

[S4v]

thanks for the replies fellas. Was just seeing if i can save some cash by using my 600w bulbs with my 1000w ballast. Later