Is this a sign of heat stress?

I have a heat problem that I think is showing in my plants. I'm doing a closet grow in a tropical country so my daytime temp under 130 watt cfl is 34C while night time is 30C. My leaves are starting to turn brown. This happened to my previous grow and my plants eventually wilted four weeks into flowering. This time I have installed an extractor fan (8"). Any other suggestions on what I can do.

this looks like it could be a potassium or iron problem heat stress will look like the leafs are twisting and the edges ruffle up and the plant may turn bright yellows check the ph of your medium

purplebud27 said:

this looks like it could be a potassium or iron problem heat stress will look like the leafs are twisting and the edges ruffle up and the plant may turn bright yellows check the ph of your medium

Click to expand...

Thanks Purplebud27. I'm growing hydro n my nutrient solution PH is between 5.8 and 6.2. I'm using general vegatative nutrients. Does pot need more potassium and iron then other plants?

I have also included more pix. the second one of of a white widow that's just stopped growing. The first one is the Master Kush which I included in my first post. Any thoughts?

now that second one dose look a little like heat stress any second opinons?

Gotta say that I agree with the second pic looking like heat stress. in addition to the twisting of the leaves, the leaves look a little more like taco's curving up a little. Also, the fact that something stopped growing means somethings wrong. Could be a million things considering i have no information like lights/container size...If you think its the heat it probably is, plus other stuff cuz those bottom leaves on the second pic look like shes telling you something

you should look into that second plant..sooner than later...just sayin

Thank you for your advice. I have dropped the PH to 5.8. I don't have an EC meter atm so can't check ppm levels. Hoping to switch to 12/12 in 3-7 days. I'm growing using:

1. 2" net pots in DWC system

2. 160w CFL which I will switch to 400w HPS for flowering

3. Using generic green and flowering nutes

4. Growing in a tropical country where humidity is 90% and temp is 27-32 C


I will post pix of my crop closer to harvest. Hope all goes well.


Smoke up & stay Free.