What kind of light for scrog?!

I want to know what would be the best watts for scrog and if HPS or metal halide is better. How high does the light have to be?
 

TruenoAE86coupe

Moderator
Light height is directly related to size of light, and how it is cooled. What we need to know to give you any kind of real answer is:
1. How big is your area?
2. How many plants do you plan of having?
3. Media (soil, soilless, hydro) would also be helpful, although not ness for light selection, but would help us get a feel of what you are planning.
4. How much power is available to your area? And are you capable and comfortable adding more power if needed.
5. How much money do you want to spend on powering this a month?
 
Light height is directly related to size of light, and how it is cooled. What we need to know to give you any kind of real answer is:
1. How big is your area?
2. How many plants do you plan of having?
3. Media (soil, soilless, hydro) would also be helpful, although not ness for light selection, but would help us get a feel of what you are planning.
4. How much power is available to your area? And are you capable and comfortable adding more power if needed.
5. How much money do you want to spend on powering this a month?
I'm probably going to be going 4x4x4 for 2 plants? Or is that too big? Not sure this is my first time with no help. I will be doing soil. I have enough power to the area I want to grow in and money isn't an issue. I just need to know the basics of getting started..
- How long to keep them on 24hr?
-When do I know to start flowering them? and when I do is it 12/12?
-Whats the temp of a 4x4x4 suppose to be at?

I cant think of anything else right now. But I will post if I have more questions lol
 

TruenoAE86coupe

Moderator
The main issue with a room that is 4x4x4 will be accessibility, your arm is not 4 foot long, so to reach the back of the room you are going to need to crawl. The other issue is plants typically need 1 gallon of container size for 1 foot of vertical growth. So 3 foot tall plants need a 3 gallon container which will stand at least 8" tall, so now you have 3'4" of total room height to include the light and plants. Most lights (hps or mh) of any size will take up a foot of room between the hood and hangers. So now you are at about 2'4" for plants and air space. Gonna be tough. It can be done but be aware of all of those issues. A couple ideas are a common container, although that presents its own issues, and t5 lighting, both of which can significantly cut down on used space. If you could make the room 4x4x5(tall) it would make it much easier on you.
You say you have enough power in the area to grow...... this is where most errors and busts (besides a friend who is pissed) happen, is not carefully planning power usage and where that power is coming from. Know your circuits well and know where you can and cannot hook up to and why. Takes some time but is well worth it, that way you know that if you trip the breaker you won't take out the furnace.
Scrog makes sizing tricky, 4 plants may serve better in that space as weaving 2 plants around that much area will be tough. Expect the plants to double to triple in height in flower, (yes after 12/12 switch) this wil be harder to judge in scrog, but that is a general rule.
Here is a good tutorial on how to do a scrog, and how to weave it.
https://www.rollitup.org/advanced-marijuana-cultivation/386597-medical-scrog-my-first-real.html

We could argue all day on temps, but i try for 75-85, some prefer 70-80, some higher for co2, some lower but most will agree with 70-80 or 85.
 
Ok, thats really helpful. So now how long am I keeping them on 24hr? I think I will be doing about 4 plants..just wasn't sure about how much room I needed. How many watts am I going to need then?!
 

TruenoAE86coupe

Moderator
You need to base how long on 24 on how much space you want to use, if you flip it when they are only 8 inches tall, they will only reach 16 to 24 inches finished, but if you wait till they are 24 inches tall they will hit 4-6 feet tall. Obviously you are going to weave a lot of this height into your screen, so that makes deciding tougher but you need to base it on how you want to use your space.
Now the light question, you have another issue with a 4x4x4 room, again there is different opinions but typically you don't want to use a 600 watt on more than about a 3x3 area, and a 1000 watt on a 4x4. Now put a 1000 watt in there and you are going to cook everything without really planning on how you are going to cool the monster, not to mention that even with an air cooled hood anything closer than 1 foot (maybe 8 inches if you plan really carefully) to the canopy. So you can see the issue here, between hanging an air cooled hood and air space you have taken very nearly 2 feet of vertical space out of use. So now you have 2 ft for your plants and containers......
Remember that even at .10 per kilowatt hour, the cost adds up quick and it is around $30 or so just to run a 1000 watt light, that doesn't include fans or anything else.
 
I know the cost is not going to be cheap. I'm going to look into what kind of cooling system I want to use. Should I go taller then 5ft? thats why I want to scrog so I don't need to go as tall? ahh this is so frustrating lol I was told cool tubes are good? never seen them before but i'm going to do some reading on them.. more advice the better. anything else I should know to get started?
 

TruenoAE86coupe

Moderator
Cooling is as important as the light. I assume you are in the US, so you are going into winter, much easier time to set up, gets tough when its over 90 outside.
In my opinion over 6' is best, but if you are building it out anyhow it doesn't cost anymore to go 8' in most cases, as everything comes in 8' lengths. If you are building it out i would highly recommend using OSB for the walls instead of drywall, much more resistant to spills etc, plus you can hang anything you want anywhere you want with no issue. Its only a few bucks more a sheet and everytime you add something it will pay for itself. Remember to build a proper grow room you need to be a jack of all trades and be able to fix, plumb, wire and plan everything in the entire room, preferably house, as a service call can be very bad any where in the house. I can answer any question about basically anything on the grow room side, feel free to ask me anything.
As far as hood, this is a very very personal choice, there is a reason there is soo many different hoods out there, everyone has their own opinion. I personally am a huge fan of the Hydrofarm Radiant series of hoods, available in air cooled (6" or 8"and not.) They have a very concentrated light pattern, they don't try to light an 8x8 area, they are more directed for a 4x4 to 5x5 area. Cool tubes are great for cooling, however the reflector is lacking. I have heard of people taking a cool tube and adding an adjuatable a wing reflector. Big $$$ to do this (probably over $300 in most cases for this hood) but then you get a completely adjustable hood to fit your area exactly, plus its cooled.
As far as fans, they are hugely expensive for anything decent, duct booster fans are basically useless, and for a hp or mh they are worthless. I use harbor freight fans, kinda loud but a little bit of insulated ducting dramatically reduces this. I will get you a link if you need it, they are about a 1/3 the price of a comparably sized fan, they are a little low on pressure, but still suck through a carbon filter just fine.
 

TruenoAE86coupe

Moderator
LoL coco if your smart. Thats pretty good. No learn to grow then worry about changing media. Soil is more forgiving, a total fail on your first grow is not a way to make a hobby of it.
 
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