Hey everyone, I had a couple of questions about growing for the first time in my backyard greenhouse with grow lights! So, I can’t really keep the plant indoors, but I built a greenhouse and wrapped it in painters tarp. I have two plant lights that are each 120 Watt BR40 bulb I got from Menards (pic of box below), but I only use one because I think as a seedling it may be too much? Also, I’m not even 100% sure the light I bought are good, so should I return it or keep using? I also would like some advice on adjusting my set up and if some people could give that, it’d be greatly appreciated. The only plant that I see potential in really is the one that’s clearly excelling over the others, should I toss the others or just leave them be? What is the recommended lighting cycle I should be following? I water them about 3 tbs a day, is that a good amount? Also does the plant that is excelling look healthy? I placed the germinated seed in soil on Friday (6/23). Please let me know guys, thank you!
I recommend you go buy some CFL’s to use instead of that bulb you’re running. You should return if if you can lol! Look for daylight CFL light bubls, on the back or side of the box look for the Kelvin spectrum rating. It will tell you what color the bulb is shining basically, and you’ll want to get some CFL’s in the range of 5000k-6500k. Again, just check the box and I promise it will be some where on there!
Be careful not to over water either, it’s easy to do!
Ideal light cycle for cannabis is 18 hours of light, 6 hours of darkness ( 18/6 light cycle ).
They look good so far! Do you have nutrients ready, because in about a week they’ll start to get hungry!
I hope this helps! I’m sure others will chime in and help you out more!
I just bought the lights the other day, so I should be able to return them haha. I currently don’t have nutrients, what do you recommend I should buy? Also, should I be using the CFL light bulbs for the entire grow or should I switch to a different one during the other stages? Thanks for the advise, I appreciate it!
Also kinda new to buying lights, do the watts matter when buying the CFL bulbs in the 5000 Kelvin range? What is recommended? How many bulbs should I have set up and how far away from the plant? Sorry for asking so many questions, just want to make sure I’m doing the best to take care of my plant!
hey hows it going. they look good so far.about the light I think 600 watt is the best. and DO NOT LOVE THEM TO DEATH. you wiil need a little nutrients and less is better. you wont see the result of what you feed it for a week or so, good luck on your grow.
Yea no problem dude, I love to help when I can!
For CFL’s, the first thing you want to figure out is what kelvin rating you need. Veg is 5000K-6500K while a CFL in flower should be in the 2200K-3500K range.
Once you know what you’re working with, you’ll then want to get the highest wattage bulbs you can find/use. If you’re on a budget, I say buy the CFL’s. If you’re ok with spending some more, look into the High Intensity Discharge (HID) lights, like High Pressure Sodium (HPS) bulbs and Metal Halide (MH) bulbs.
I personally use a 600w HID for my veg tent, and 2-300w MarsHydro LEDs for flower.
The problem you’re going to run into is that you’re growing outdoors, and the lights are running off electricity, so I would be concerned about leakage and electrocution! I think you’ll be fine with just using the sun since you’ll be outdoors!
Take bulb and clamp back. For 67$ you can get a roleadro 300w 2nd gen 125 actual watts. I got one, light will be great for plants. But, really, with three plants you should get two lights. One will work for vehg but once you switch to flower, you’ll need two lights. You can get them from Amazon. As for nutes, I use general hydroponics Flora trio, start at half recommend dosage, then slowly add more. You can get that from Amazon for about $30. Good luck
I just put one in my amazon cart, thanks for the post @HornHead
I’m with @ktreez420 and sharing his concern about electrocution and fire hazard with growing outside with the kind of lamp you have. (300W LED corn light bulb you show in another topic, @professordank)
It have to have outdoor specifications, it’s imperative, and, so your clamp reflector, and, if you really want to grow in a home made greenhouse, build one that will be at least 2’×2’×6’ or 3’×3’×6’ for your 3 plants.
Hoping that’s helping you…
~Al 
I don’t think I’m going to end up growing 3 plants in the end. Two of them seem fairly weak and may not survive. Do you think I’ll still need to build a new greenhouse if I have one plant only? Thank you for the reply!
@Niala sorry i forgot to tag you
Yes, without any doubt, you need height space… Do not forget that a cannabis plant, depend on the strain(s) you have, a plant can grow between 2.5 feet to 5 feet (7+ if it’s a pure sativa)
You’ll need space between the canopy (top of the plant) and your lighting system… So, a 6 feet in height is a minimum, even if you’re adventuring your self in some of a more advance way of growing like LST ( Low Stress Training), SCROG (SCReen Of Green).
And it must be water tight if your intention is to use indoor light(s) in an outdoor home made greenhouse. And that’s one more reason why you need a more spacious one… Even if LED do produce less heat, it does produce some, enough to a fire hazard with a painter’s tarp… You’ll need at least 1 foot clearance from the top of your greenhouse and the top of your lamps(s) and about 6" of clearance from the side of your greenhouse and the reflector… Even if only 1 plant survive…
Hoping that I respond to your question @professordank, do not hesitate if you have more questions, I and other’s are willing to help as much as we can for helping you succeed…
~Al
Great advice al!