400w or CFL or ???

Garzal

Member
Is it possible for me to use a 400w HPS in a 48x24x24 grow tent with and intake(50cfm) and outtake(100cfm) and one oscillating fan and keep acceptable temperatures, or should I look at downgrading, or possibly CFL? I just dont like the thought of figuring out how to make a good CFL configuration.
 

themistocles

Well-Known Member
Best way to figure it out is to just set it up and take temp. readings at different heights. The you'll know for sure.
 

appleseed

Active Member
My 400w kicks enough heat that I'd be concerned about a space that size with nearly any venting. if the pot is 18" tall and the plant is 18" tall that leaves 12" for the light to hang in. I'd think it would burn the tops... Maybe if you're planning to lst or other really low hieght grows sog scrog....
 

Garzal

Member
scrogs are REALLY interesting .

http://forum.grasscity.com/advanced-growing-techniques/48363-scrog-method.html

however . why do you NEED a 400 w ??

you could always just grab a 150 or 250 HPS/MH and go from there .

I have a 600w myself . its amazing !! but to be honest I would have rathered something slightly smaller . (400/250) .

good luck with all your adventures !
THIS is basically the reason I want to use 400 watt, because its really cheap. IF someone can find me a similar deal for a 250 watt I would take that one too. Unless people think that a HID will output too much heat for my setup then I will settle for a CFL configuration.

And I don't know about scrogging now, I was thinking about doing it before, but I plan on using DWC and I think that a scrog would be hard to implement, I might try some lst though.
 

blakkmask

Well-Known Member
THIS is basically the reason I want to use 400 watt, because its really cheap. IF someone can find me a similar deal for a 250 watt I would take that one too. Unless people think that a HID will output too much heat for my setup then I will settle for a CFL configuration.

And I don't know about scrogging now, I was thinking about doing it before, but I plan on using DWC and I think that a scrog would be hard to implement, I might try some lst though.
thats not a bad deal. BTW, Its 115.74 w/ Shipping. I have an IS account. The 250 HPS from HTGSupply has a 4 sided reflector, not a batwing and a BRAND NEW ballast , not a refurb, for 138.78 w/ Shipping. They Also have the 150 HPS for $85 w/ Shipping But they seem to be sold out at the moment.
 

Garzal

Member
Kind of bumping for more opinions, does anyone think that it would get too hot for my plants especially in DWC? Should I just be safe and go with CFL or will it be okay?
 

ow.douglas

Well-Known Member
You don't say what size container you are using or the number of plants. In my opinion 400W is overkill for 4 sq feet and it is going to generate heat problems and those small fans are not going to fix it. You will need to upgrade that reflector to an air cooled unit and get another lager fan just to cool the light. I have a 2x2x4 tent and I use T5's in it, is it perfect? In a word, no. You can eliminate MOST of the heat issues and you can also get more space because they are very close to the plants, 1-3 inches. Take it for what it's worth and good luck with the grow.
 

ataxia

Well-Known Member
You don't say what size container you are using or the number of plants. In my opinion 400W is overkill for 4 sq feet and it is going to generate heat problems and those small fans are not going to fix it. You will need to upgrade that reflector to an air cooled unit and get another lager fan just to cool the light. I have a 2x2x4 tent and I use T5's in it, is it perfect? In a word, no. You can eliminate MOST of the heat issues and you can also get more space because they are very close to the plants, 1-3 inches. Take it for what it's worth and good luck with the grow.
Do you use t5's through veg and flower???? I've been debating getting a 400 for a 2x4x5 area but heat is an issue. Then i debated on getting a 250 but they are just as much as a 400.
If you use it in flowering how is the bud density that you're getting?
 

ow.douglas

Well-Known Member
Ataxia, you can use the T5's for flower, are the buds as dense as HPS? No. Where I live it gets pretty hot, even in my basement workshop in the summer. I have to use a different system in the winter and summer. I know that the 400 is about the same cost as the 250 but, the HID lamp generates about 3.4 BTU per watt. If you get the larger light and don't really need it you will spend all of your time fighting heat. In a tent it's even worse. If you can veg in the tent with T5, 18/6 and 12/12 with the HID in the open room it's easier to control the temps for both. That's my experience anyhow, I hope this helps some and or course, your results may vary.
 

mcgyversmoke

Active Member
I love CFL'S just for this reason i am beginning to set up my grow box which will be h60"xL36"xW24" and im going to be using 6 large wat CFL'S 3 105w 5700k and 3 80-105w 2700k all through veg and flower. All im doing is makin a hanging piece of plywood with 3 y sockets in it. and the lights all together costed a lil under 100$. ive seen great results with cfls if you use enough like im trying to do and all my venting is a homemade can filter with a comp fan to pull air out and an oscillating fan to keep them stems strong. and a few minor things.
So in the end id recomend a few cfl's if your worried about heat and since your plants will almost touch the lights when done you wont have to worry as much about torchin them.
my opinion though.
 

Garzal

Member
The plan is to use a ten gallon or so tub to grow 6 or so plants DWC in that tent in a closet. Now when I look at T5 it just seems like they have so few lumens, Wouldn't it be better to set up a cfl configuration with 6 or so 42 watt CFLs and get more than 1.5x the lumens? That is how it seems to me at least. I dont like the idea of configuring CFLs but if HID is mostly out of the question, I will.

I love CFL'S just for this reason i am beginning to set up my grow box which will be h60"xL36"xW24" and im going to be using 6 large wat CFL'S 3 105w 5700k and 3 80-105w 2700k all through veg and flower. All im doing is makin a hanging piece of plywood with 3 y sockets in it. and the lights all together costed a lil under 100$. ive seen great results with cfls if you use enough like im trying to do and all my venting is a homemade can filter with a comp fan to pull air out and an oscillating fan to keep them stems strong. and a few minor things.
So in the end id recomend a few cfl's if your worried about heat and since your plants will almost touch the lights when done you wont have to worry as much about torchin them.
my opinion though.
Where did you buy your CFLs at?
 

ataxia

Well-Known Member
Ataxia, you can use the T5's for flower, are the buds as dense as HPS? No. Where I live it gets pretty hot, even in my basement workshop in the summer. I have to use a different system in the winter and summer. I know that the 400 is about the same cost as the 250 but, the HID lamp generates about 3.4 BTU per watt. If you get the larger light and don't really need it you will spend all of your time fighting heat. In a tent it's even worse. If you can veg in the tent with T5, 18/6 and 12/12 with the HID in the open room it's easier to control the temps for both. That's my experience anyhow, I hope this helps some and or course, your results may vary.
yep yep .. that's my main problem right now .. I'm using cfls but heat is becoming an issue as the weather gets warmer. I'm thinking of using a different room all together but heat will still be an issue growing here in the summer... SHIT.. so i'll be holding off on a 400 for sure this summer
A better question.
AND BTW. THANK'S FOR EXPLAINING THE HEAT OUTPUT OF HIDs
So how much ambient heat would be generated by a 250??
I can add up the btu's but i'm not familiar with the comparision to temps.
I know it's a loaded and pain in the ass question but If you can answer that'd be a great help.
ALSO. Do you have any pics of your plants grown under the t5. I haven't seen many if any grows here with t5s straight through.
 
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