Leaves curling - low humidity

Hey all -

I thought I solved my humidity problems with an air conditioner in the room, but moving my light closer to my girls has cranked the heat up a bit.

Setup:

1mx1m hydrohut
600w HPS in a 6" aircooled hood, ducted to outside the hydrohut
light is warm to the touch, can put my hand over my girls and back doesn't even really get warm
thermometer on pots says ~80* and 0% humidity
500CFM fan exhausting hut just using screened vent in back


Plants leaves are curling, I'm afraid I'm going to kill them. I was thinking maybe they were rootbound, I water them every couple of days.. but the low humidity was scaring me so I was spraying water on them. I'm thinking the water spray is hurting the leaves? But the plants are getting hot I guess.. I mean, I just don't understand. All I've read is if the lights don't make your hand too warm, they should be OK for the plants. But this doesn't seem to be working. I've also tried a humidifier and it seems to have about no effect on humidity in the hut.

Any ideas here? I'm on an extremely limited budget (as in I can't spend any more money right now).

just curious are u using any nutrients and what kind of soil are u using?

Fox farm soil, advanced nutes micro/grow/bloom, mixed in the lightest solution on the back, cut down to 20% of that.

I see roots coming down out of both containers now - I'm going to transplant into larger buckets tomorrow.

I changed the ducting on the hut - it is now as follows:

8" inline fan used as intake, blowing into a 8-6" reducer through aluminum ducting into the hut and onto the plants. This has dropped temps CONSIDERABLY with the AC going on in the room, and it gets good movement from the plants. The upside to this is the humidity is fluctuating - it still drops to unmeasurable levels, but spikes close to 30% sometimes.

6" inline fan ducted to 6" sealed hood sucking air from inside the hut, blowing over the bulb and out the top of the hut. Temps fluctuate between 71-75 now.

I think I've got temp under control now, and the hood is 18" from the top of the plants (HPS light, 600w lumatek ballast). I think this is the right combo - I just need to maintain humidity.

At least I know that I can DROP humidity all I want for flowering..

z3r08urn said:

Fox farm soil, advanced nutes micro/grow/bloom, mixed in the lightest solution on the back, cut down to 20% of that.

I see roots coming down out of both containers now - I'm going to transplant into larger buckets tomorrow.

I changed the ducting on the hut - it is now as follows:

8" inline fan used as intake, blowing into a 8-6" reducer through aluminum ducting into the hut and onto the plants. This has dropped temps CONSIDERABLY with the AC going on in the room, and it gets good movement from the plants. The upside to this is the humidity is fluctuating - it still drops to unmeasurable levels, but spikes close to 30% sometimes.

6" inline fan ducted to 6" sealed hood sucking air from inside the hut, blowing over the bulb and out the top of the hut. Temps fluctuate between 71-75 now.

I think I've got temp under control now, and the hood is 18" from the top of the plants (HPS light, 600w lumatek ballast). I think this is the right combo - I just need to maintain humidity.

At least I know that I can DROP humidity all I want for flowering..

Click to expand...

your problem is your roots ran out of room to grow.

GrowingNoob - you were 110% correct!

I saw the roots sticking out of the bottom of one of the pots (tiny plastic things) and knew one was rootbound. Turns out both were. I xplanted into 4 gallon buckets with a mixture of fox farm, black gold and turfking (don't ask - I'm poor and it's what I had/could afford). The plants rebounded in less than a day, and one plant with EXTREMELY curled leaves (the smaller one) is getting bigger and growing like mad.

I'm feeding them a 50% solution of AN Micro/Grow/Bloom right now and they seem to be eating it up like crazy.

I placed a bowl of water in the hut with an airpump, and I got the humidity up to about 40% (I think part of that is the soil giving off moisture, too) and it's nice and cool in the hut. Things are going well, and I'm looking forward to harvesting a bunch of clones!

Thanks for the help guys! I really, really appreciate it!