First indoor grow, need some light on a few questions.

mixchemical

Active Member
Hello one and all! :)

I've just started my first grow, I have 3 seeds that have been germinated and put into small cubes of rockwool (drained in 5.5 Ph water for about 1.5 hours before the seeds got planted).

Up untill that stage all is great but here is where I can't find ANY information. How should I proceed now?

I've got a grow tent that has a 400W MH bulb atm (at max height) and i've got the cubes of rockwool sitting in 3 seperate domes and the bottom. My RH is around 40-80% (I need to get some stable humidity, I know) and temperature is ranging from 24C to about 29C which is a lot, I know and im not sure what is causing the spike in temperature.

The seeds have been in rockwool for about 10 hours now and we'll, I can't really check on how they're doing.

But my question is: Should they be kept under a light? I'm running my MH at 12/12 which I'm going to run untill harvest (it's an autoflowering strain).

Also, do you think the seeds have taken some damage due to the high temperature?

Any tips you can give me will be greatly appreciated :)
 
i'd take 18 hrs of lights on (growing) vs 12 hrs.

Yeah, I see your point but like I said, I just read it and thought it made sense :) I'll adjust it to 18 when they've sprouted out of the rockwool. No need to adjust before that right? It won't really make them grow faster since they dont use the light.
 
so have the seeds sprouted yet?

We'll, they are germinated and they all have a taproot showing but none have made an apperance over the top layer of the rockwool. So in that regard, no. I'm just trying to get my temperature stable. Does humidity affect temperature, in a negative way? Since when i spray the inside of the tent with water, the temperature drops. So is that my problem? That I don't have a stable source of water so the humidity is high.
 
After switchimg the light to 18 give it about a couple of day y and you will see them skyrocket

Yeah i'm sure :) Right now I'm just worried that they won't make it. The temperature is fluctuating, humidity is doing the same. Just need to get it straight how they should be treated in the stage after germination but before they've grown leaves.
 
Yeah, I see your point but like I said, I just read it and thought it made sense :) I'll adjust it to 18 when they've sprouted out of the rockwool. No need to adjust before that right? It won't really make them grow faster since they dont use the light.

i would keep the lights on 24 now then. will be easier to keep your temps/RH in check. then when they sprout, go down to 18/6
 
i would keep the lights on 24 now then. will be easier to keep your temps/RH in check. then when they sprout, go down to 18/6

Why would 24 make any difference now before they've sprouted? Im just trying to understand since they wont be able to use the light im producing. It's just generating heat at a rate I need to get under control, so im just seeing that 12/12 or 18/6 would be more viable, so they have a "cool down" period. Just trying to understand your logic behind it :)

i'm not a huge fan of rockwool. i start my seeds in rapid rooters. they kick ass.
Yeah, I tried to find them where I live but couldn't so rockwool was the "last" choice for me :) Shouldn't be a problem with the medium, I hope, I've taken quite good measures to make sure they're saturated correctly and at the correct Ph.
 
Hello one and all! :)

I've just started my first grow, I have 3 seeds that have been germinated and put into small cubes of rockwool (drained in 5.5 Ph water for about 1.5 hours before the seeds got planted).

Up untill that stage all is great but here is where I can't find ANY information. How should I proceed now?

I've got a grow tent that has a 400W MH bulb atm (at max height) and i've got the cubes of rockwool sitting in 3 seperate domes and the bottom. My RH is around 40-80% (I need to get some stable humidity, I know) and temperature is ranging from 24C to about 29C which is a lot, I know and im not sure what is causing the spike in temperature.

The seeds have been in rockwool for about 10 hours now and we'll, I can't really check on how they're doing.

But my question is: Should they be kept under a light? I'm running my MH at 12/12 which I'm going to run untill harvest (it's an autoflowering strain).

Also, do you think the seeds have taken some damage due to the high temperature?

Any tips you can give me will be greatly appreciated :)
Do you have a exhaust fan for air flow? I had hell without one and had some of the same problems with heat and humidity.
 
Do you have a exhaust fan for air flow? I had hell without one and had some of the same problems with heat and humidity.

Yep! I've got it setup like this. Carbon filter - duct - cool tube (400W MH) - duct and then exhaust out. I've got no intake fan though, just relying on an opening which I open up when the light is on, since the pressure is negative (?) it should suck in air by itself if i'm not mistaken.
 
Yep! I've got it setup like this. Carbon filter - duct - cool tube (400W MH) - duct and then exhaust out. I've got no intake fan though, just relying on an opening which I open up when the light is on, since the pressure is negative (?) it should suck in air by itself if i'm not mistaken.
What Cfm is your exhaust fan? Size of your tent?
 
Yep! I've got it setup like this. Carbon filter - duct - cool tube (400W MH) - duct and then exhaust out. I've got no intake fan though, just relying on an opening which I open up when the light is on, since the pressure is negative (?) it should suck in air by itself if i'm not mistaken.
Actually had to covert C to F for temp and you said your running 24C to 29C. That is pretty good in my opinion. They say optimal temps are in the 70-80*F range so you aren't to far off at 24-29*C.
 
Its a TT125UN, rated at 280m3/h at max rpm (4,6m3/min)

My tent is 90x90x160cm which comes to about 1.3m3

I've calculated at about 20% loss, due to ducting but I still should be venting the tent at least every minute.
 
Its a TT125UN, rated at 280m3/h at max rpm (4,6m3/min)

My tent is 90x90x160cm which comes to about 1.3m3

I've calculated at about 20% loss, due to ducting but I still should be venting the tent at least every minute.
In my opinion i think your temps are within range. As for that much light i think its a bit much for seedlings at this stage. They dont require very intense light.
 
In my opinion i think your temps are within range. As for that much light i think its a bit much for seedlings at this stage. They dont require very intense light.

Yeah, I know that running at 400W MH maybe a bit overkill right now but I don't have any other solution sadly and they're not getting hit by any heat either so i'm trying to take the best precautions I can.
 
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