Two 250 watt cfl one at 6400lum one at 2700 lum

I have a 32×32×63 tall tent will a 250watt 6400lum work for flowering and 250watt 2700lum work for veg or do I need to go with different lights all together

So far that does look good but more specifics would be helpful. Do you have the proper color spectrum in your bulbs? What kind of lights are you using?

I now see they are cfl, so as long as the color temperature is correct you should be fine. You are towards the lower end for required light and could add some lower watt ones for side lighting. Personally I think the more bulbs the merrier and I would prefer 4x60 watt bulbs with equal lumens to just one 250 watt light. What you have sounds good and should be enough for a respectable crop.
Good luck.

I think you mean 6400K, not lum. 6400K and 2700K, ‘K’ is short for Kelvins, it is a “temperature” color rating, not at all the same a lumens.

In general, the lower the number, the more yellow, orange or red-ish the light is, and the higher, the more blue.

You might just have barely enough light for that size area, if you use both for flower which is perfectly fine.

Also you kind of have the numbers backwards, 2700k is redder, and is for flowering, and 6400K is blue-er and for veg.

You would keep the 6400K close to the plant for most of the veg period, and then add the 2700K light when the switch to flower begins, with both lights relatively close but equal distant to the canopy.

happy growing,


Since youre in a rather small grow space I would reccomend staying with fluorescents. Other lights can add some serious heat to the room, including root temperature, which is rather detrimental. You also have to keep the lights further away from the plant so as not to burn it. Where as with flourescent lights you can be inches away. Be sure you have the correct light spectrum and adequate wattage and lumens for each grow period.

Strive for a minimum of 3000 lumens in veg and 6000 in flower. Go higher if you can. In veg you want your color index to be around 6500k and flower around 2700k. There are ways to use both or even just one for the entire grow, but basically thats what needs to happen.
Good luck.

With HPS you probably want about 350 watts for your size area, you could maybe use a 250 watt HPS with decent results.

Either way, with these CFLs or HPS, you are going to have a lot of heat to deal with.

I’d probably stick with what you got, because the lights you have are not cheap either. Or if money is no object, get a 500-600 watt LED that uses around 250-350 actual watts, This would probably be the best when it comes to creating not too much heat.

See our recent discussions on light here:

Since I don’t have as much experience with HPS, I’ll have to answer with this, as far as I understand it, HPS does put out the most heat of the bunch near the bulb, this is partially due to the red spectrum, HPS puts out a lot of Infra Red, which is also known as heat.

However the ballast that runs a HID light like the HPS, also puts out a lot of heat, but this ballast is usually outside the grow area and does not contribute as much to the grow area’s heat, depending on how you have your grow area set up.

With those 250 watt CFLs, the ballast is built into the base of the bulb, and those things put out a lot of heat themselves, even if the actually fluorescent spiral tubing isn’t putting out that much heat.

Which will actually contribute more heat to the growing area? It is hard to say. I’d like to hear from people that have used both. I know when I used CFLs in my 4 foot by 4 foot wide and 6 and 1/2 feet tall tent, and these were just 2 x 65 watt CFLs to supplement my LEDs, the heat was unbelievable from only approximately 130 watts of CFLs. I ended up instead adding another 150 actual watts of LED to my tent for more actual intensity in usable light(more lumens or PAR) without a over all noticeable increase in temperature to my main LED light, as was not the case with those florescent lights.

You just can’t really get around having near 50 watts per square foot of grow canopy, no matter the type of light, and that amount of electricity is going to create some heat that needs to be planed for and dealt with, even with LEDs. They’ll produce the least amount of heat per watt, but they can get quite warm as well.

Mac…Will here…
you know pretty much what I have gone through with useing the two 1000 watt hops for flower. I can tell you that the heat that came just from the ballasts them selves was unbelievable. And then the lights , we’ll it got to the point where I had to make big decisions as far as lighting went. And that I have you to thank…BIG TIME!!
I still have what you sent me and if it’s ok with you. I will share it with others.
Now that I have changed the lighting I see a much better result.
I now use two 400 watt hps lights and my grow much cooler.

Thank You Mr. MacGyverStoner

B Safe

Thank everyone on their input that helps alot