flowering under a 600 watt HPS bulb with ballast dimmed down to 400 watts

Mcoocoo

Well-Known Member
A 400 watt bulb at the 400 watt setting would be ideal.
I got an email back from the manufacturer and they said that a 600w ballast set at it's 400w setting will power a 400w bulb , although the lifespan of the bulb will be diminished because the ballast will still draw 600 watts from the electrical panel no matter what the dimmer is set to. They said what happens when you use the dimmer is that it cools the bulb and lowers the lumen output. They didn't go into any detail as to how the ballast accomplishes this or where the extra 200 watts go. I am guessing that the extra current is turned into heat that is held inside of the ballast itself, making the ballast warmer and the bulb cooler. (that is my guess anyhow) They also said that I should use the correct wattage bulb with the correct ballast for maximum lumen output and efficiency. So, were they telling me that it is safe to use it that way? I don't know
 

Mcoocoo

Well-Known Member
Sounds like a bullshit answer to me.
Yeah I agree. Anyhow, I emailed them back and asked them if the spectral output would be correct if I did use a 400w bulb in in the600w ballast dimmed to it's 400 watt setting and they emailed back with a message ALL IN CAPS, that said: (the 400 watt lamp performance will not be consistent as the bulb may blow out in a matter of weeks or months). So now I been able to raise the light up as high as I can get it, and I have gotten a good handle on the temperature. I can get it down to 71 degrees in there and I am trying to see if that will counteract the intense lighting, so I am still using the 600 watt setting, but I do dim it down when I feed because I have to raise it up about 4 inches each time onto a piece of wire racking placed over the top of pan to catch the runoff, then I turn it back up to 600w when I put the plant back down on the floor. So far so good, buds are filling out and seem to be frosting up in defense of the high light level, (like a sunscreen).
 

Mcoocoo

Well-Known Member
I tied down the side branches and raised the light to the top of the tent which is almost 7 feet high, but plant is 32 inches inside of a 12 inch fabric pot, I may have to bend the top
 

Lord Bonkey

Well-Known Member
I tied down the side branches and raised the light to the top of the tent which is almost 7 feet high, but plant is 32 inches inside of a 12 inch fabric pot, I may have to bend the top
what size exhaust fan do you have running? whats the canopy temp
 

Lord Bonkey

Well-Known Member
3x3x7 is 63 cubic feet
so even a 4 inch canfan should be enough to keep that tent cool with that light on full
you will want a fan blowing on and under the bulb too depending on what you use for a reflector

but 600 watt hps is perfect light for that tent
 

Mcoocoo

Well-Known Member
what would make them so sensitive to the light. The highest that I can get the light is 22 inches from the top of plant. And the reflector is a bat wing, with no glass
 

auswolf

Well-Known Member
Don't dim a 600w bulb, you will loose a shit load of lumens. Always use a 400w bulb on a 400w setting.
Don't listen to a sales rep........

Here's a pic showing my light height.(2x600w 400v hps)
IMG_20191008_125321.jpg
 
Top