Grow box too hot for newly planted seeds. 90 degrees plus!


#1

Hey guys! First time on here, hoping to get a little help. Anyway, seeds germinated great, once tap root was shown they were planted and placed in my box. The issue is with the lights on and fan I’m at 88-92 degrees farenheight and 28% humidity. I’m worried these little gals aren’t going to sprout. It’s only been about 36 hrs but I know I need to fix this quick. Should I turn the lights off until it breaks the surface? I have a passive intake at the bottom with a fan to pull in cool air. On the top opposite side I have two 4"x4" holes for hot air to escape. Any help/comments are appreciated.
White Widow Autoflower.
Happy Frog Soil
Ph 6.5
8 out of 11 cfl’s on at this point. Over 100 degrees F when all are in. Thanks in advance guys!


#2

Well. Many ideas pop out here. You don’t need that many CFLs going to light soil…

Temps in the 80’s are great for propagation; So, this is not the reason. I just think you are being impatient in regards to 36 hours of waiting.

You are going to have to buy a vortex style 4" fan and ducting, or cut back on your lights until you get into the low 80f range. :smile:


#3

That sounds good man thanks for the help. I’ll pull a couple out to try and get the heat down somewhat. I will give it more time, I didn’t think they would be up yet, I just meant I don’t want to have them in the heat much longer as it has already been 36 hrs. Any ideas on adding some type of added co2 to accommodate the heat once they are above soil? I have read added co2 will help with higher temps, but also trying to keep this as simple as possible brewing as tho it’s simply personal stash bud. Thanks again!


#4

I notice you say you only have an intake fan at the bottom. What type of fan? Passive intake? But you also do have a fan to pull in cool air?

You should have a centrifugal fan, or as Latewood called it, a “vortex” fan, and this should be sucking or pushing the air out of a top vent on the box, to most effectively remove the hot air, while sucking cool air in through the “passive” inlet at the bottom. We need the over all inside dimensions, or cubic feet to figure out what size fan would be best and how many cubic feet per minute need to be removed to help keep temps down. But a 4 inch would probably do, I assume this “box” isn’t that big. CO2 can only help a little with the heat and it will add that much more complexity to the grow. For most people, the air has plenty of CO2 in it and if you are completely turning over the air inside the box, the oxygen created by the plants will be removed and plenty of CO2 rich air from you breathing in the dwelling you keep this box in, will be pulled into the box.

Also increased CO2 is not good for seeds, or clones, the roots need oxygen.


#5

Thank you for the response, that was very informative. You’re right lol, I would rather not add the complexity. The fan I have is just a small personal desk fan that I started out in front of the bottom intake holes assuming the hot air would flow up and out with that fan pulling in but it probably isn’t strong enough. The box it 22x22x44, so not large. One of the plants has now sprouted so I was extremely excited to see it up and out. I can’t wait to check in the other when I get out of work. These vortex fans? Something from a hydro store? Hardware? I read a lot about old pc fans but seems as though he fan I have is larger than that. Thanks again you guys, having this first seedling above soil has my excitement through the roof.