Second Light questions

Hi All,

Quick question about lighting. I am vegging 8 plants in a narrow, but long basement room (3' X 20'). They are current vegging in 8, 1 gl grow bags but I plan to put and finish them in 5gl smart pots. I will be transplanting into the 5gls in about 2-4 weeks or whenever they are ready. I currently have 1 600W MH/HPS in an air cooled hood I am using to veg. It's perfect right now, but I realize I am going to need a little more as things get bigger (plants are only about 3'' high now but incredibly dense foliage). In only 3'' of vertical growth, there are 3-4 nodes which is crazy compared to what I have seen/am used too. I have a great 6'' inline fan & ventilation system so cooling isn't an issue (especially since winter is right around the corner). Temps are about 75 ON 70/68 OFF.

Here lies my question:

What should I do about a second light? Should I swap out the 600W bulb/ballast and put in a 1000? Should I get another 600W + Hood and set it up in tandem with my current one? Should I get a 400W? Or how about some CFLs or LEDs as supplemental lighting?

I guess the most obvious choice would be to get another 600watter.. but the increased power bill sorta scares me though I can get over that. If I do get a 600 watter, I would do 4 plants under each light. That's about 150 watts per plant, a lot more than the 100watt norm I read about. Is that too much light or can you not have enough light?

Any thoughts/ideas are greatly appreciated guys!

4 small plants under one 600w is perfect during flowering, I would add that second 600w when you are ready to flower, and make sure you add venthilation to that one too.

Yea, that's what I figured people would say. Seems like the best bet given my space constraints. I didn't know if folks had any better ideas. Thanks man!

Well it really depends on how long you're going to veg them for, the bigger they are the more light coverage youll need to penetrate the whole plant. How high up is the ceiling? How tall do you want them? What strain?
If they're heavy indica then you won't need any more unless you grow them bushy and need to space them out more. If they're heavy sativa then you might want to try to spread the light out more because they will grow tall and will need light along the sides ( you can hang some fluorescents and have them lower down between plants).
The thing about light is the plants need CO2 to use it, and if you're not supplementing CO2 when you have a ton of light then it'll be wasted. Without CO2 you won't need more than 8000 lumens per square foot. With what you have said it looks like you have about 6500 per foot if you're using 3' x 4' of that space. Honestly you won't notice a big difference unless you also add CO2. But if you want you could add some fluorescents for more coverage.

A second light would be ideal, but if your really afraid of the electric usage then have you considered a light rail-mover?

windsurfer420 said:

Well it really depends on how long you're going to veg them for, the bigger they are the more light coverage youll need to penetrate the whole plant. How high up is the ceiling? How tall do you want them? What strain?
If they're heavy indica then you won't need any more unless you grow them bushy and need to space them out more. If they're heavy sativa then you might want to try to spread the light out more because they will grow tall and will need light along the sides ( you can hang some fluorescents and have them lower down between plants).
The thing about light is the plants need CO2 to use it, and if you're not supplementing CO2 when you have a ton of light then it'll be wasted. Without CO2 you won't need more than 8000 lumens per square foot. With what you have said it looks like you have about 6500 per foot if you're using 3' x 4' of that space. Honestly you won't notice a big difference unless you also add CO2. But if you want you could add some fluorescents for more coverage.

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I plan on vegging them for a while, probably 2 months starting from right about now. I am going to top, and do LST. They will be in 5 gallon smart pots. The celing is about 10 feet tall - plenty of room. They are all hybrids, 5 Cali Connection Original Sour Diesel, 1 Reserve Privada Kandy Kush, 1 Reserve Privada Purple Wreck, and 1 G13 labs Sour Jack. Like I said they are all hybrids so I assume medium growth? But I got plenty of room. I am only doing 2 runs this year, so I want them to get big to increase yields per grow. I'd say I want them to be around 4-5 feet tall. Is that reasonable?

I've thought a lot about getting CO2. I have the perfect setup for it.. pretty sure the room is like 99% sealed.. its essentially surrounded by concrete except the steel door which I could air proof. The only thing I worry about is the cost, heh. C02 system + another 600watter is a lot of money but I realize the yields are incredible with it.. Ahhh so many decisions!.

We'll I hope I answered some of your questions and I really appreciate any further advice you can provide bro.

corvetteguy said:

A second light would be ideal, but if your really afraid of the electric usage then have you considered a light rail-mover?

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I have considered one. I spent about 3 hours one day researching everything I could find about light movers and results. Essentially I found that they are great for veg, but not so good for flowering. Plants certainly can use all the direct lighting they can get and the light mover reduces quality/quantity.