+ Rep for proving me wrong. I have seen some expensive digital ballasts on the market with a "plus 10% electricity" setting to get more light out of the bulb in expense for life expectancy. I would never have thought, the bulbs could handle 33% extra without melting down.

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Yeah I'm pretty sure it's as bright in my garden now with the 400w lamp and 600w ballast as it was with matching 600w lamp and ballast. I know for sure something is happening cuz my 400w lamp and 600w ballast set is giving off as much heat as my matching 600w set up did. I know that dosen't necessary mean it's just as bright, but I'm pretty sure I'm pulling 600w by how hot my extenstion cords are and my room temps.

If your extension cords are even warm it time to UPGRADE THEM to 30 amp rated ones. Warm cords mean BAD BAD things!! Fire will destroy everything and possibly send you to jail.

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It is far easier to ignorantly control others than it is to wisely control yourself.

I have some pretty thick hospital grade extension cords. Just that I turn my electric heater up as if I were running a 400w system which caused the overload. Things are normal now that I lowered the heater as if I were running a 600w system. Temps are a stable 65 lights off and 70 lights on.

But thanks NoDrama. I'll look for the 30amp rated ones. I never really read the labels. I just usually get the thick ones with the lil light on the end if you know what I'm talking about. Someone told me those are "hostpital grade" whatever that means. I just explained the deal (electric heater heating up cords) to my local hardware guy and he showed me those.

If I'm not mistaken, its the length of the cord that had something to do with it as well.

i like cheese!

btw u should be good ride it out till ur new bulb gets there but just incase keep a constant eye on the light

Yep, you are correct, the longer the extension cord the more resistance it has, and that is part of the reason longer cords get warm if you aren't pulling a lot of amps thru them.

I don't know whats wrong with my 600w lighting system. It keeps blowing my 600w bulbs but not the 400w bulbs. Anyone else ever have a problem where bulbs keep blowing out? The 600w bulbs wont last one day. They blew by the following "on cycle". I have it on a 15amp rated timer. I never had a problem with my 400w system and my 600w ballast w/ 400w bulb are fine as well.

Are they the same brand ? Are they the Digital Greenhouse brand from HTG ? Those bulbs are supposed to suck bad. I'd try ordering some different bulbs from somewhere and see if you get a different result.

Just for shits and giggles I went and fired up a 400 W HPS bulb in my Lumatek 600 W ballast, ran for 5 mins, everything seems just fine.

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It is far easier to ignorantly control others than it is to wisely control yourself.

Well yes and no. I did order this: http://www.htgsupply.com/viewproduct...roductID=48956 but the ballast is Digital Greenhouse the bulb is a GrowBright 600 watt HPS Bulb. Are they the same company?

The 400w bulb is a Slyvania HPS 400w bulb you can get at your local hardware store (US).

The GrowBright 600 watt HPS bulbs are the ones that keep blowing out.