400w MH losing brightness after a few weeks?

[Soulrust]

Hi,

I have a 400w MH lamp with a magnetic ballast (400w). I remember when I first turned it on, about 3 weeks ago, I was astonished to see how bright it was and how well it lit up my grow box (mylar covered) - it was straining for the eyes to look inside the box.
Now, 3 weeks later, it seems quite a bit dimmer. While it's still hard to look straight at the bulb for more than 2 seconds, the grow box isn't as bright, and doesn't strain the eyes - not much anyway. I can keep my hands about 4" from the bulb for at least a minute without much discomfort, though it IS hot.

Two things that may have contributed to this:

* I had one hot start, I didn't really know that you were supposed to let it cool. I think I tried lighting it for about 30-60 seconds before I turned it off and read about hot starts.
* At the start, I kept the ballast at the top of the grow box where it got REALLY hot - you couldn't keep your hands on it for 5 seconds without serious pain. I now have it on the side with a fan blowing on it and it's nice and cool.


Then again, it is of course possible that I've somehow acclimated to the light and it hasn't changed, what do you guys think?

 

[MyMeds4Me]

1- Your plants will have grown there for absorbing more light and less refraction
2- One hot start would shorten life but not to the extent your figuring
3- Cooking the ballast may have weakened the output.

IMO I would test the light output and see if I had a drop in lumen, lux and PAR reading. If there is a drop and the light is now out of spec I would start off buying a new bulb (cheaper than starting with the ballast). The Bulb will need to be replaced every so often and time frame varies on bulbs and ballast.

4- I would spend the money on a digital MH/HPS ballast and unless your using this for just veg I would also go with the HPS, the girls are gonna want the 2000k range that the MH just cant produce. JMO