New Grow of 4 Northern Lights (1st Time Grow)

[HonestGR]

I’ve got 4 northern lights seeds and would be looking to maybe get the 4 of them up abd running as i read these were one of the easiest plants to grow , I have a full spare room cleaned out and ready to go so have a full empty room for 4 plants

I would definitely go with a 4x4x6.5 ft tent. It will give you some room and at the same time, if tou decide to grow more, you can still sog (sea of green) the tent. And fill out even more.

Air Exhange, based off the size of tent, you will want a fan capable of moving 30 cfm of air. This will prevent issues like mold etc. (Number provided has been increased by 25% to calculate in a charcoal filter.)

Now lights, you will want to let me know the type of lights you wish to go for....

HPS- Cheaper up front, bulb changes (maintinance), more power used, you will need to vent to remove heat, but more yield.

LED- Expensive up front, little to no maintinance, most are rated to 50,000hrs (generally cannot be repaired). Less power, less heat, decent yields with newer models as they come out.

QB- So far I do not have experience with these, so someone else may need to help you here. (I will get some exp soon enough).

Hopfully this helps. There are lots of companies that offer "package deals" I would have a look online to see. These are just the basics. You then need to look at grow medium you wish to use, nutrients, pH pens etc etc.

At least this is a start my friend!

 

[Steviestash]

For exhaust you want at least 3 times your tent volume 30 cfm not enough you need around 300cfm

 

[HonestGR]

• I will correct slightly.... but still still rexommend 41.66cfm. Depending on the type of light he selects.

4x4x6.5 = 104 / 3 = 34.666...

34.666 x 1.20% = 41.6 cfm

People always overshoot the cfm, although its not a bad thing. The 41.6cfm is right. This is venting his room every 3 minutes, which is ample. As long as it has negitive pressure he is good. I always say to overshoot slightly with a speed varying fan to adjust acordingly.

How to calculate a grow room cfm requirement:

• Multiply the width and length of your grow room times the height to get the total cubic feet.
• 
  
• You want to exhaust all the air every three minutes, so divide your total cubic feet by three.
• 
  
• For every 1000 watt of HID lighting, add 10% to your CFM rating.
• 
  
• If you use a carbon scrubber, add 20% to your CFM rating.
• 
  
• Add 1% for every foot of duct tubing you use to connect your exhaust fan to the scrubber.

 

[Steviestash]

• I will correct slightly.... but still still rexommend 41.66cfm. Depending on the type of light he selects.

4x4x6.5 = 104 / 3 = 34.666...

34.666 x 1.20% = 41.6 cfm

People always overshoot the cfm, although its not a bad thing. The 41.6cfm is right. This is venting his room every 3 minutes, which is ample. As long as it has negitive pressure he is good. I always say to overshoot slightly with a speed varying fan to adjust acordingly.

How to calculate a grow room cfm requirement:

• Multiply the width and length of your grow room times the height to get the total cubic feet.
• 
  
• You want to exhaust all the air every three minutes, so divide your total cubic feet by three.
• 
  
• For every 1000 watt of HID lighting, add 10% to your CFM rating.
• 
  
• If you use a carbon scrubber, add 20% to your CFM rating.
• 
  
• Add 1% for every foot of duct tubing you use to connect your exhaust fan to the scrubber.

Agree with everything here except for 41cfm being enough if you just times it by 3 then that should give you enough extra for the length of ducting you might run the carbon filter and lights as an easier way to figure it out with giving you some extra so you can adjust

 

[HonestGR]

Agree with everything here except for 41cfm being enough if you just times it by 3 then that should give you enough extra for the length of ducting you might run the carbon filter and lights as an easier way to figure it out with giving you some extra so you can adjust

I do not dispute that. This is litterally no ducting and bear minimum. Bends in the ducting reduce a large % of airflow. All of my tents have at least 1 bend in them. (I cannot recall the exact % value, but it is significant. Air is treated as water when it comes to the calculations) I would use a 150- 200cfm fan. Smaller are quite a bit harder to find. Plus if you ever modify (ie led to hps) it is nice to have that extra leeway. Dont forget the speed adjuster!


A lot of companies advertise the fan cfm being far higher than actually what needed. As long as you get that full air exchange every 3 minutes your good. If your adding C02, this does change everything!