lighting question

Discussion in 'First Time Marijuana Growers' started by Dustinsin, Sep 23, 2010.

  1. Can I throw my seedlings that are 3.5 days old from seed under a 400 watt mh? They popped there heads out of the soil last night. I have a 4x4 tent that stays around 84F with the light on. I just dont want to give them to much light, and I know I should use floros but I dont have any!

    also not sure how long I have to use this damn heat mat and dome.

    advice please!
  2. yes you can use it just don't get it real close yet. give them time to get a nice root set then start to lower it down.

    if your tent is staying warm I don't really see a need for the heat pad.
  3. Thanks Bender.
    What about the dome? Do I need it after they pop there heads out?

    I have a ventilation question too if you would like to squash it!
    im using a 4x4 sun hut, is 340 CFM enough extraction power to turn the air around every 3-5 mins? The fan seems loud enough, this has to mean its working right?(Just kidding) it is an Eco-plus classic 6".

  4. Take the volume of your grow space (in cubic feet) and multiple by 5 (for a 5x air exchange). That's the minimum CFM you need for it.

    Your grow space is 4*4*X (whatever X is)
  5. woOpps! That makes sense... Its 4x4x7. So thats 560 CFM. So im short 220 CFM. Should I just buy a better fan? damn.

    I do have a booster fan thats 134 CFM. raaaar still short even if it would help huh... Input always appreciated.


    Thanks Friedguy!
  6. I believe that booster fans installed after your main fan will only slow down the airflow if their boosted flow is lower than the flow of your main fan. After so much airflow, the booster just gets in the way. 3* your volume is probably fine, I just like a shit load of air exchange, and you'd have a whopping 4 CFM to spare :D

Share This Page