HPS lamps destroying my plants

Hey so I grew two little babies til they started showing white pistils. I switched them to a flowering cycle and I used a HPS lamp which I’ve never done before. I didn’t have an extraction fan or Andy fan inside for that fact and it burnt the !@#$ out of my plants. Pretty much the whole top canopy is gone. I trimmed all the yellow/brown leaves off and switched them back to veg cycle (18/6) to get them back again cause I only had them on flower for 1 day. I was just wondering how far my lamp should be from the canopy and if I had an extraction fan would that help to?

Yes having an extraction fan would help a whole lot. You also want a oscillating/circulating fan circulating air between the canopy and the light. With HPS light it is real easy to tell if the light is too close, hold the back of your hand at the level of the canopy, If the heat is too hot for the back of your hand, it is too hot for the leaves, you’ll need to raise the light higher until you can keep your hand under the light without it getting uncomfortable. You can use the underside of your forearm, kinda like testing a baby bottle, the skin on that part near your wrist will be a little more sensitive if you want to be extra safe.

:smiley: I could not have said it better myself! LOL

Great info.

your HPS did not burn ro kill your plants; It is the fact that you did not research how to use an HID lamp before you grew.

We are here to help, and widh you good luck in the future

Okay so I did do my research actually.

I was just told things and read things that were wrong. I’m not exactly how sure to keep the lamp from my plants because no matter what height I set it at it still feels fine on the back of my hand/ forearm. So that’s no help at all. I mean in feet, cm, mm anything but saying the back of your hand. And the extraction will probly help alot but I haven’t set it up yet cause it sounds like a !@#$ing key engine.

In other words don’t say I haven’t done my research. I’ve been growing for 3 years indoor and outdoor. I’ve just always done cfls cause they are so much cheaper. I just don’t know much about HPS lamps. I just need a few little bits of info. Distance from canopy? (Actually measuring unit) is it true that one HPS lamp is better than a few cfls??? And three, will I need a fan aiming at my light to cool it down???

If the heat of the light isn’t making your hand feel too warm it shouldn’t be burning your plants, the plant should be able to grow very close to the light if the temp is under control. Sorry don’t know what more to tell ya there, lol. The burning of your leaves might be from something else then. I’m assuming if you have no extraction fan you have no idea how hot it is getting after a long time in the, well you haven’t even told us what size room, tent, closet nor what wattage of HPS, nor even what the plants are growing in, we can’t give you a lot of specifics if you aren’t giving us any.

Let’s get you started with a support ticket, answer all the relevant questions and we might be able to get an idea of what is going on. The more info we have the better we can help you.

ILGM Support Tickett

What is the strain?
Indoor or Outdoor?
Size of space?
Soil or Hydro? Medium used?
Type of nutrients used? NPK? PPM levels?
Humidity %?
Light system/watts?
Vegetative Growth season or Bloom/Flower season? Number “weeks/days” from start of veg growth or into flowering?

What is the strain? Cheese Fem and Mazari Grape Reg
Indoor or Outdoor? Indoor
Size of space? 40x40x120cm
Soil or Hydro? Medium used? Hydro. Coco Lite
PH? 6.4
Type of nutrients used? NPK? PPM levels? Sensi Grow A + B and Sensi Bloom A + B
Temperature? Ranges between 13-19 degrees Celsius
Humidity %? Ranges between 50-70
Light system/watts? CFL 250 watt and HPS 400 watt with ballast
Vegetative Growth season or Bloom/Flower season? Number “weeks/days” from start of veg growth or into flowering? Veg for 1 month then flowered for 1 day and that happened.

You did not give us the strength of your solution. That is a key factor.

Yes the EC/PPM concentration of your nutrients is a very important detail. Your temperature and humidity vary a great deal. Is there a reason for this? Is this night versus day temps and or night vs. day humidity? 70 will be a bit on the high side especially later in flowering, you don’t want to get bud rot or molds/fungi. And it would be better to get your PH down to about 5.8 for hydro.

Hi Kane

i used to use HPS ok the min temp in a HPS set up should be no less than 60 degree F the max should be no more than 80 degrees F get a little digi temp thing ,Im in UK and they cost max £3 thats maybe $6 …

Ok the thing with HPS is that if the light is too strong it burns , and also you cant wet spray plants as it burns also ,
on the flip side if its not strong enough or too far away the plant will just keep growing and growing and not go into bud ,

Once you get the overall temp under control , ue an intake fan and an extract fan , I used a 6 inch intake and one 4 inch extract for every 4 plants , be careful of this as the extracts smell the area they extract to for try set it so the natural wind direction blows it away.

ok height of lights what i used to do was set the HPS lamp normally a 400W at a min of half the height of the plant or plants it was above plus 18 inches

so for example if i had a plant at 3 feet (900 cm) i would set light at 18 inches (450cm) plus the additional 18 inches (450cm) , so it would be at 3 feet (900cm) in this case ,Most of my plants grew no taller than 4 feet approx (1.2m) so my lights would be max 1m (just over 3ft) above them .

I will stress you can spray feed under HPS as it burns the solution on the leaves

If I got a plant that looked like it was growing to high I was more inclined to bed the top over rather than raise the light , Gently bend not cause a crease that would cause the top to be starved ,for example I would use twine to gently pull top down

I have now switched to LED and wish I hadnt problem after problem with them

Andy (KiltyK)