HPS does bulb wattage have to match fixture

I checked out a source for HPS fixtures they have 400 w bulbs in them now Can I use a 250 w in the fixture does the ballast have to match the bulb? or is it not that complicated. this will be either for a second cabinet or a upgrade from the CFL's in my current 20"d x 40"w x 6'h cabinet.

A friend thinks a 250w HPS in my small cab will burn the plants... any other opinions. since he hasn't grown any other than a few random plants out side that never reached maturity.... not that I have lol this is my first.

 

If you can maintain a good foot too a foot and a half between ya plants and lightin then you wont get light burn and as for the heat burn you only need good or clever venting to draw the heat out of you set up.
Hmm good question on light packs coz I cant answer it and same thing has crossed my mind before.

 

they have to match, only exception is conversion bulbs..

 

My cabinet has an exhaust fan so I doubt heat will be an issue. Now that it has been said That I will need to use 4oow Not sure if that will be too much.... I have 400 w equiv in CFL's right now.... but they run cooler and aren't as intense as hps.

 

just for a second reassurance on that...............the bulb wattage HAS to match the ballast wattage. I told that to a buddy who didn't believe me who was running a 70W HPS ballast, blew the 70W bulb, and could only find 50W replacements......he went ahead and used the 50W and after only like a minute and a half he said the bulb fuckin exploded...........hes so lucky he was home and not using a bigger bulb......talk about FIRE HAZARD!!

Anywho, yeah a 400W would be very hard to control the heat in that space you would be at about 70W per sq. foot tho! lol.........but no if this is your first go around with a HID and that space is your only option get a 250W kit or just stick with your fluoros.......

 

Thanks for the info, gonna stick with the floros they seem to be doing well

 

Lol I'm using a 400 in a pretty small space and I'm pretty sure its gonna workout more than perfect, but ambient temperatures are low and ventilation isn't a problem for me..

3 feet wide, 3 feet deep, 5 feet in height.

 

you have double the space my cab is only 40wx20dx70h

 

If i was you i'd just add one low wattage 70-150 watt hid trust me you wont regret it. And if heat becomes a problem just stick a bathroom extraction fan by ya hids light.

 

I just want to reinforce the point that useing mismatched ballest and bulb will cause explosion, and could start a fire.