Hey brother, could I get you to create a new thread when it comes to asking questions like this? It lets us give you more individual attention to your question and it helps to not take away from the OP's question and discussion about his topic. I totally know you didn't mean this intentionally so don't think you're in trouble or anything; just a friendly reminder and request! Thanks bro!
Now, on to your question!
How big is your actual growing area? Are you attempting to utilize all square footage of that 7 x 7 area? 7 ft x 7 ft = 49 square feet. On average, you want to shoot for around 50 watts per square foot in veg and a bit higher than that for flowering (these are not set in stone, just what I would consider to be generally accepted numbers.)
I just found your grow table picture from your intro:
What's the square footage of your table? Is that 7 x 7? If it is indeed 49 square feet, then take your 400W and divide it by the square footage you want to cover, and that gives you 8.16 watts per square foot. Not going to cut it. Double that with your second light (and this next number isn't totally accurate since the light placement will affect the watts per square foot,) but 800W divided by 49 sq ft is 16.32, which is still pretty low.
If your table is a 4 foot by 4 foot (16 square feet
@400W = 25 watts per square foot
@800W = 50 watts per square foot
If your table is a 5 foot by 5 foot (25 square feet
@400W = 16 watts per square foot
@800W = 32 watts per square foot
Just something to keep in mind while you're figuring out your setup!
One 400W HPS/MH will produce a TON of heat. I see you have one vented hood; is your other fixture a vented hood as well? What are you planning on doing for intake/exhaust? Were you planning on just having them hang open air with no duct? Two HPS non-vented will BAKE your plants unless you take some appropriate steps to direct the heat away from them.
As to which one (HPS or MH) to use; I think you'll find traditionally most people use the MH for veg growth (which takes better advantage of the blue'ish spectrum,) and HPS for flowering (reddish spectrum.) You'll find some guys use MH through their whole grow, some use HPS through their whole grow. Some of the differences I've seen noted on here between using the MH vs HPS during veg is usually how the nodes space out and the amount of stretch that occurs. Personally I like "tried-and-true" when it comes to someone having their first go-around with growing, but once you're comfortable with the procedure you can always switch them up yourself and get first hand experience as to what works best.
I also noticed on your intro that you stated you were interested in the gas lantern routine for your light schedule. Would highly recommend
not doing that bro, if at least not on your first grow. There's a lot of controversy on whether or not it's feasible for growing and it most likely (in my opinion) would cause more stress to your plants than good. The typical grow schedules for autos are generally 18/6 (18 hours lights on, 6 hours darkness,) 20/4, or 24/0. I would recommend 18/6 or 20/4 on your first time around; 24/0 lighting is better for winter months or when you have a handle on your environmental conditions.
With summer coming up; you can help combat some of the heat by timing your "lights on" to be more during the evening, when the temperature naturally drops a bit. Then time your lights off to be during peak daylight hours, where the sun is the harshest (and making your room easier to cool without having those lights beating down.)
Is your grow room going to be enclosed at all or is it a big open room like in your picture? Carbon scrubbers work best in a negative air pressure environment, which could be tough to achieve based on some of the conditions you've listed.
Give us some details bro and we'll get you set up straight! :karma Cloud:
What's your question or what are you having trouble pulling the trigger on? I'll try to help you! :I Need Tech Help:
