Autoflower Grow Under 300 Watt Mars LEDs

Majikoopa

Well-Known Member
Greetings fellow growers!

I've been out of the swing of things for several years and BOY has the technology improved. My last serious grow was probably in 2010 and, from what I recall, LEDs were still a novelty back then and cost mega bucks to purchase. Although I still have my nice fluorescent grow lights I used to use, the grow space I have available to me now is TINY... which is cool because I've always enjoyed the challenge of producing in a small space.

I was pretty happy to see that the Mars 300 Watt LED was so affordable, so I went ahead and purchased onefor roughly $70 after reading some pretty positive reviews everywhere I looked. Purchased a second when I heard they only have a 1.5X1.5 foot coverage area. Here's how my setup is going to look, please tell me what you think because I'm new to LEDS:

-I've got a small grow space, roughly 2' deep by 3' long. The height is limited to about 5 ft.

- Since the space is small, I'm using two 300 watt LEDs by Mars, considering they are supposed to have a 1.5' X 1.5' coverage during flowering, 2' X 2' during veg. In my box, that means I'll have 3' X 1.5' of space fully covered by direct light during flower, 4' X 2' covered during veg.

- Since it's a small space and due to coverage/height concerns, I'm going to plan on using autoflowering plants. Specifically, I'm trying out some autoflowering Carmelicious and autoflowering Northern Lights. The seeds are feminized.

- I'll coat the walls in panda plastic, grow my plants out of 2 gallon pots, and mount the lights evenly spaced in the grow room to ensure maximum coverage. The lights will be hooked up to a timer on a 20-4 cycle during the grow from start to finish... I know there's a lot of debate over what kind of light/timing produces the most quantity vs. quality for autoflowers, so I understand this may be a point of contention. I will also run the light on "veg" mode for the first half of the grow, then switch it to the "flowering" mode as the buds start to go into production.

- I'm thinking I can really only get away with two plants in this space.... since they're autos maybe 3? Probably not though. I figure each plant can have its own light and I'll get two healthy, productive plants out of the deal :)

- I like to keep things simple in terms of growing medium so I'm doing two 2 gallon pots filled with Happy Frog organic soil, bat guano, earthworm castings, mycorhiza, perlite, and some happy frog fertilizer-- veg at first, "fruit & flower" later on. Will water with 6.8 ph water. The water quality is excellent where I live, so have never bothered buying bottled water/RO/distilled etc. Will sprout in a lightly moist paper towel sprinkled with mykos.

-For air circulation, I've got a small air filter that I'll run in the box to provide a bit of breeze for the girls and keep the smell down. I'm planning on putting this on the same cycle as my lights to give them a little break at "night".

- I have a shelf above where the plants will go that I'm planning on fermenting some sugar water in 2 liter jugs with yeast and aquarium lines running down to the plants. The biproduct of early fermentation is CO2, so I'm hoping this gives the plants a little edge by "enriching" the small box a bit.

- I expect the grow to go anywhere from 8 to 12 weeks long.

So yeah, that's the plan. HPS or majorly large size grow box/ducting/etc. isn't really in the cards right now, so LEDs paired with autoflowering, femenized seeds seemed like a nice solution to growing in the tiny space I have available.

Thoughts anyone? Just seeing if I'm on the right track with this or not.
 

Tim Fox

Well-Known Member
sounds like you have put allot of thought into this,,

are you venting the grow box?,,, sounds like you have a fan inside the box,, but are you moving air in and out of the grow box?
have you sprouted seeds yet?,,,
have you ran a few light cycles in your box with the timer and a temp thermometer,, to see what your high temps and low temps are during any given time?,,,
 

Majikoopa

Well-Known Member
sounds like you have put allot of thought into this,,

are you venting the grow box?,,, sounds like you have a fan inside the box,, but are you moving air in and out of the grow box?
have you sprouted seeds yet?,,,
have you ran a few light cycles in your box with the timer and a temp thermometer,, to see what your high temps and low temps are during any given time?,,,
Hey TIm Fox,

Thanks for the reply! I'll answer your questions in order:

1. No, not venting the grow box. From what I've seen in some grow videos, the LEDs won't produce enough heat to really require it. If it does, for some reason, get super hot in the box I'll definitely do that. For now, just the fan/filter in the box to move some air around.

2. I haven't sprouted the seeds yet. Need to finish my build out of the grow box and wait to accquire them from the seed bank first.

3. Have not ran the light for a few cycles, but planning on doing that. I've got a thermometer with a high/low memory so that's actually a really good idea!
 

Tim Fox

Well-Known Member
IMG_7491.JPG i happen to own a mars 300,, ( its out in the barn dont use it anymore),,I like the light just fine, and I keep it as a spare now, and it threw off lots of heat, i even changed the fans out on mine to make it quieter,, i have pictures of that change if you want, in fact mars lights make more heat than cobs do,, simply because of all the diodes ,, you will be surprised how much heat 2 of those are going to put out,,
that is why i suggested the test run before you sprout seeds,, ,,

many people grow with mars,, it will work fine, all lights fit on a scale someplace,, and mars are an affordable entry for many growers,,
Easy right,, I like easy,, in fact i am rather lazy,, lol


if your grow box will not go above say 85 degrees with both lights on, then you will probably be alright,,
i am saying this because I have been thru this,,, TESTING is your best friend right now

here is a picture of my grow box back when i had the mars hanging in it,, just to show you i am legit,,
 
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HighLowGrow

Well-Known Member
When you are doing your testing, you might want to fill your pots with soil and get em wet. Stick them in there. See what kind of humidity readings you get.

20/4 is good
2 gallons. Perfect for two plants in there.
Happy frog is good.

I think the CO2 thing is overblown. Got to say though, I haven't tried it myself, therefore I will stop talking. :bigjoint:

Looks like you have a great plan.
 

jeepster1993

Well-Known Member
I have a little 2x2x4 clone tent with a Mars2 300 in it(180 wall watts).
Does fine for this use in this size tent. The tent does need to be vented though, but is pretty small for a fan, so the fan is sitting on the top of the tent, it works.

 
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