1k hps to close??

I have an agro sun 1k hps under a bat wing reflector and the lamp is now just 10"s above my biggest girl. No signs of heat stress or leaf burn. On the contrary she is reaching to get to it or should I say growing/budding strongly. About 16 days on 12/12. So what do you all think? To close? The lamp has less than one month of use. Almost new. Have two and this is the second one used only for one month on last grow...

For some reason your plants don't seem to be receiving the typical amount of light emitted by a 1000w. No plants can handle being closer than about 16" to even a generic, properly working 1k unless something blocks a portion of the light. The glass may not be 100% transparent or, more likely, the ballast may not be putting out enough power. The ballast should only be tested by a professional electrician as the high power level is very dangerous.

im sure some will agree that plants "cant" be closer than 16inches to the light

I've had lamps that close. No big deal. Watch for bleaching though - slower onset than burning/canoeing and sometimes it's hard to tell with the naked eye. Take it out of the light every once in a while and check.

If it looks right it is right. Right?

some of mine are closer than 16in but my lights are air cooled

Cooling is irrelevant to minimum bulb distance. The min. distance to bulb is based on when light burn sets in. Heat concerns can increase the distance required between bulb and plants but the minimum distance possible stays the same.

Put your hand out flat with the tip of the plant touching your palm, so your covering the top of the plant. Leave it there for a while, if it gets to hot your to close. Back of your hand to the light, it's more sensitive than your palm.

You are correct! I do now see just a bit of heat stress in the very upper fans. Have backed it off about 4 inches. As for the other guy. The lumens are 5x5. Meaning I have checked them and all is working nominal to profile. Your idea of how far a light should be is based on advice not experiance or you just can't understand it. My strain handles very high ppms as well so maybe it is your weak genetics that make it hard to understand. One other thing too, If you took time to read my post you would have seen "bat wing" what might that tell you. Oh u were finished well then allow me to retort! I don't have dirty glass to worry about. To funny..

lowerarchy said:

I've had lamps that close. No big deal. Watch for bleaching though - slower onset than burning/canoeing and sometimes it's hard to tell with the naked eye. Take it out of the light every once in a while and check.

If it looks right it is right. Right?

Click to expand...

Does a little bleaching on the plants directly under the light outweigh the effects of suboptimal light on the outer edges of the light?

And on a reread I don't seem to see the minimum req to prevent light burn/bleachind, any idea/