Marijuana grow, switched from MH to HPS, now leaves are burnt

A question from a fellow grower:

I’m writing this letter because few days ago i found a bad surprise on my plant’s leaves.
Nobody is able to understand which could be the reason.
I describe you my growbox details.

120 x 120
600 watt hps
25 celsius

Unfortunatly i coudn’t acheve a taller humidity during my veg period that i switched to bloom just yesterday.
I guess that the problem could be caused by the fact that i’ve switched from MH to HPS without moving the bulb further than before.
And so i guessed it could be a burning problem, added to the clime too dry.

Move your light up if it feels hot on your hand it feels hot on your plants Glaire.


Changing lamps should not be the issue. However; If you changed photo periods and the plant stretched taler in a couple days; You could be too close. It is not merely the lamp change.

Fill this out and we will have another look. :wink:

Seedbank used:
Indoor or Outdoor?
Size of space:
Soil or Hydro?
Medium used:
EC/TDS ppm levels:
Humidity %:
Light system/watts?

It’s 7 critical kush under 600watt hps in a 120x120 growbox
I always keep ph level between 6 and 6.5
The temp is around 23’celsius and humidity 60%
I’ve fertilized the plants with bio roots for the first 2 weeks,
Alga grow just for veg xiod and i always use hesi sux vit once a week for all plant’s life.
From the first day of bloom xiod i start with alga bloom plagron 2times a week.
Unfortunatly i don’t measure ec and tds

This is 8th bloom day
The problem seems to be overtook

OK. Issues I have with your regimen:

  1. PH for hydro is 5.8, PH for soil is 6.5. ^.0-6.5 is too high for hydro; Too low for soil. This could be the start of the issue. Do you grow Hydro or Soil?

  2. I have never heard of the nutrients you are using. Perhaps if you posted a link to the info, we could look at it, and give you an opinion.

  3. I am not sure what you mean; “The problem seems to be overtook”? Hard to tell anything is wrong with the yellow overtones from your lamp.

Awaiting your reply. Peace