Things have been chilly at night, so I added a mini heater on low. this morning the plant was fine and green. I turned off the heater in the morning, and I checked them later (5 hours later) and found browning on the edges, near where the heater was.
Medium is peat, vermiculite, perlite, with fertigation at 1.3EC of peters peat special and tap.
This is the plant this morning with no visible issues.
And this is the plant a few moments ago, with the visible browning
Was the heater near or pointing in that direction? Looks like some heat or wind burn … 
Thanks¡ yeah i was worried about how fast it manifested, or maybe if anyone has had heat stress look like that. hopefully its just a minor thing, ive removed the heater for now…
Same as letting the plants get too close to the lights (guilty of that). Oops, time for an adjustment.
try putting the heater further away with an oscillating fan blowing the heat toward the plant-- spreads the heat more evenly without a burn!
Electric heaters inside the tent can drop the rh dramatically, I did the same last winter and seriously stunted a plant, brown leaf edges and wilting.
so youve had something like it? i relocated the heater far away from the plants. fortunately RH was in control during the night.
thanks¡
Yeah point the heat away and have a fan moving it around
The trick to running a heater in a small space is radiant heat(I use a hot plate set to warm) small cool mist humidifier behind it a fan infront blowing the air to the other side long ways. Exhaust to the side the heats on so the floor fan makes the air circle. How I keep my kitchen tent warm in the winter.
Yeah I think my mistake has already been pointed out, poor air circulation and a too bigger heater.
