400w bulb with 250w Ballast

Hi Guys,

I have just noticed that my HPS bulb is 400w, where as my Ballast is 250w. I loaned the gear from a mate and he said that's how the shop supplied it to him.

I was considering changing the bulb as it has done 2 grows so should I buy a 250w or 400w bulb?

After reading a few threads about ballasts on riu, the general opinion is never go for a bulb wattage that is higher than your ballast wattage as it may shatter or be a fire hazard.

Any thoughts please?

Tks

use the appropriate bulb for the ballast

My friend gave me what he said was a 750w ballast and reflector, so I got a 750w bulb for it, when I looked it was only a 600w ballast, I thought that surely it's better to have a higher rated bulb than the wattage it's getting, as opposed to lower. I used it for the flowering stage of one grow with no problems, but then got the correct size bulb and to my eye it does seem a little brighter.
I would say for best results, always match power ratings on any electrical equipment. Better to be safe and all that.

its more dangerous the other way , using a ballast with a higher rating than the bulb but i would still reccomend using the bulb that matches your ballast it will run better

muffin said:

Hi Guys,

I was considering changing the bulb as it has done 2 grows so should I buy a 250w or 400w bulb?

Click to expand...

Two grows seems a little soon to replace the bulb. That was probably 16-24 weeks for 2 flowering cycles. I usually replace my bulb (400 watt hps)after 9 months and put the old one on the shelf as a spare in case of an early failure by the new bulb. I also have noticed no visible degradation of the bulb at the time of replacement. Anybody else want to chime in on bulb time and degradation?

I hear you wont be able to see a diference, just use the chart or better yet do what you do. I hate not knowing the lumens and have to get a lumen meter. Lol, to tweak out some where else besides the plant when I am watching them grow. Better than tv.

use the same ballast wattage as your bulb, there is a reason every bulb has it clearly marked the recommended ballast to go with it. Sure, you might not run into any problems, but you are still at risk of running into a serious electrical malfunction that can not only destroy your crop but lead to a more serious electrical fire that can burn a lot more.

Better safe than sorry in this situation.

Thanks guys... very much appreciated.

I brought a 250 w Bulb today :~)

I read somewhere that you should change every 2 grows, can't remember where but if they last 9 months + then I won't be changing this one for a while.

Thanks again.