Hi 420, I have a 30"x30"x60" tent w/cfls and would like to know if a 400 watt hpsw/reflector is too much for my size tent? I have found complete kit priced nicely @HTG but until recently I assumed that I didn't have enough verticle space for that size bulb. I am currently finishing up a DWC grow and I have one hempy in there that started 12/12 from seed. Four weeks into flowering as of today. I saw on a video someone had a 400 hps sitting right on top of his girls with no burns. His reflector had a glass bottom the only thing keeping them from touching the bulb. I value the advice here on 420 and wanted to run this pass every looking today. Please share your thoughts, I want this thing by Tuesday.
400 hps ballast in a tent
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Lusi
New Member
I'm going through a similar phase of this as you... new grower ready to get the big lights. Since I just bought my light (finally!), I still have all of my info saved and can share it with you if you want to save some of your time and headaches. That 400w light you saw so close to the plants was likely water cooled, or a well set up 2 in 1 air cooled. (others can say more)
My 2 books agree on a 400W for a 3x3 area, but with a higher ceiling. You're a bit tighter than this... and also have a shorter tent. I'd consider a 250W, or a 400W that dims to 250W. This way you'll have the bigger light for later upgrades. Ah, I found an option you might like! Lumatek dimable ballast 400W down to 250W. Retails at $189, plus hood, build, etc etc. If that 400W dims to 250W and is equal in power draw and other things (other people will know more here) My total cost for my 600W light, 6" air cooled hood, Lumatek 600W dimable digital ballast, and entry level bulb were just over $300. My local hydro shop matched price with the internet and I'm glad to give them my business.
If you're in a hot climate like me, you'll have to vent the heat out and possibly the intake in the summer. One, you absolutely must have an air cooled hood, no matter where you live. I've learned venting the air into the room the tent is in is not enough to cool my 4x4x6.5' tent. If I open the doors and windows in that room, in the winter, it's still to hot! 72 degrees is the goal here.. Turns out a hole under the carpet in the closet to the crawl space is easy enough. Same to an attic. If you can't do this, don't get the 400!! If you haven't looked into all the other lighting options, folks here will fill you in here. You might find some better options than HPS for that size.
I have my new light in the garage right now, since my new tent has a fricking rip. It's set at 400W. The outside temp is 32, garage is 52! 2 car, vaulted roof, no insulation. Every little hole shines out light like a UFO. That's a LOT of heat.
I hope this helped some.... GL!!
My 2 books agree on a 400W for a 3x3 area, but with a higher ceiling. You're a bit tighter than this... and also have a shorter tent. I'd consider a 250W, or a 400W that dims to 250W. This way you'll have the bigger light for later upgrades. Ah, I found an option you might like! Lumatek dimable ballast 400W down to 250W. Retails at $189, plus hood, build, etc etc. If that 400W dims to 250W and is equal in power draw and other things (other people will know more here) My total cost for my 600W light, 6" air cooled hood, Lumatek 600W dimable digital ballast, and entry level bulb were just over $300. My local hydro shop matched price with the internet and I'm glad to give them my business.
If you're in a hot climate like me, you'll have to vent the heat out and possibly the intake in the summer. One, you absolutely must have an air cooled hood, no matter where you live. I've learned venting the air into the room the tent is in is not enough to cool my 4x4x6.5' tent. If I open the doors and windows in that room, in the winter, it's still to hot! 72 degrees is the goal here.. Turns out a hole under the carpet in the closet to the crawl space is easy enough. Same to an attic. If you can't do this, don't get the 400!! If you haven't looked into all the other lighting options, folks here will fill you in here. You might find some better options than HPS for that size.
I have my new light in the garage right now, since my new tent has a fricking rip. It's set at 400W. The outside temp is 32, garage is 52! 2 car, vaulted roof, no insulation. Every little hole shines out light like a UFO. That's a LOT of heat.
I hope this helped some.... GL!!
400 hps ballast in a tent?
Set the ballast outside of the tent.
"Sealed' air-cooled reflectors help a LOT. So does pulling that cooling air from outside of the tent, passing it through the tent, and back outside as opposed to pulling the air from the tent itself.
Set the ballast outside of the tent.
"Sealed' air-cooled reflectors help a LOT. So does pulling that cooling air from outside of the tent, passing it through the tent, and back outside as opposed to pulling the air from the tent itself.
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- #5
I'm going through a similar phase of this as you... new grower ready to get the big lights. Since I just bought my light (finally!), I still have all of my info saved and can share it with you if you want to save some of your time and headaches. That 400w light you saw so close to the plants was likely water cooled, or a well set up 2 in 1 air cooled. (others can say more)
My 2 books agree on a 400W for a 3x3 area, but with a higher ceiling. You're a bit tighter than this... and also have a shorter tent. I'd consider a 250W, or a 400W that dims to 250W. This way you'll have the bigger light for later upgrades. Ah, I found an option you might like! Lumatek dimable ballast 400W down to 250W. Retails at $189, plus hood, build, etc etc. If that 400W dims to 250W and is equal in power draw and other things (other people will know more here) My total cost for my 600W light, 6" air cooled hood, Lumatek 600W dimable digital ballast, and entry level bulb were just over $300. My local hydro shop matched price with the internet and I'm glad to give them my business.
If you're in a hot climate like me, you'll have to vent the heat out and possibly the intake in the summer. One, you absolutely must have an air cooled hood, no matter where you live. I've learned venting the air into the room the tent is in is not enough to cool my 4x4x6.5' tent. If I open the doors and windows in that room, in the winter, it's still to hot! 72 degrees is the goal here.. Turns out a hole under the carpet in the closet to the crawl space is easy enough. Same to an attic. If you can't do this, don't get the 400!! If you haven't looked into all the other lighting options, folks here will fill you in here. You might find some better options than HPS for that size.
I have my new light in the garage right now, since my new tent has a fricking rip. It's set at 400W. The outside temp is 32, garage is 52! 2 car, vaulted roof, no insulation. Every little hole shines out light like a UFO. That's a LOT of heat.
I hope this helped some.... GL!!
Great info Lusi, sorry I am just getting back to this. I have been sooo busy and I just discovered my subscribed thread section 2 days ago. LOL. After I did some more research I have realized what you have mentioned above. Thanks for the 189.00 deal that sounds really nice. Do you have a link to that site? I wouldn't mind taking a look at that. I do plan on upgrading my tent size to accommodate a 400hps with ease, but I would like to see what I could use asap and I think you have helped me with that. Thanks again for the advice, talk to ya soon.
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- #6
LOL, I know I did say ballast in a tent, but I only meant the bulb and reflector portion
And yes the air-cooled reflector sounds like a good option. Thanks for the advice. Looks like I have several options to ponder over. I appreciate the responses.Hydrogrown
New Member
So did you end up getting it? I bought a 400w switchable setup but the light isn't cooled, I cool it with a floor fan blowing its heat up towards my 180 cfm exhaust fan. With the closet door open I keep temps around 80 degrees or lower. I definently should have thought of how I was going to exhaust heat and bring in cool air to the closet before I started but you can make it work if you have too though. Good luck.
Delta-Nine
New Member
Standard blueprint is 50w per sq ft. 2.5'x2.5'= 6.25 sq ft 6.25/400w=64 w per square ft. A 3'x3 would put you around 44 w per sq ft.. Not that a 400 wouldn't do well in a larger space but as I stated that is just the blueprint.
In a previous thread I read that you can take the wattage of the light here 400 multiply is by 3.2 and then divide it by the cfm of the fan. This will tell you how many degrees your space is going to heat up from the light itself. I was looking at the 400w dimmable myself for a 26x20x54 atleast in the top half flowering box. I plan on using a vortex 6'in wiht a 6' charcoal carbon filter the fan is rated 450 cfm. So following the formula (400x3.2)/450=2.84 or 3 degrees higher than the ambient tempeture of the room. Hopefully this will be cool enough if not I'll have to switch down to 250w 
I want dense buds 
This is my first box (made from a coca cola machine) and first grow ..just getting ready to order the supplies ..I found the ballast for 134.89 on Gruw Works Hyrdoponics and they have reasonable shipping by far the best deal I have been able to find.
New here but looking to stay around awhile....
Wake n Bake
I want dense buds This is my first box (made from a coca cola machine) and first grow ..just getting ready to order the supplies ..I found the ballast for 134.89 on Gruw Works Hyrdoponics and they have reasonable shipping by far the best deal I have been able to find.
New here but looking to stay around awhile....
Wake n Bake
- Thread starter
- #10
So did you end up getting it? I bought a 400w switchable setup but the light isn't cooled, I cool it with a floor fan blowing its heat up towards my 180 cfm exhaust fan. With the closet door open I keep temps around 80 degrees or lower. I definently should have thought of how I was going to exhaust heat and bring in cool air to the closet before I started but you can make it work if you have too though. Good luck.
Hey Hydro. I haven't made any new purchases. Still rockin the cfl's. I will upgrade with a larger tent and hps lighting later this year, along with a larger exhaust/filter. I'd rather be able to get everything at once so hopefully by fall I will start rockin some fat dense buds. 12/12 maybe 10-15 of them that is my plan. I like what I'm getting with the cfl's though just short of 2 ounces dry with single cola and about 8 lateral branches with some nice nuggets at the tips decent popcorn for other sites. I guess I was supposed to trim more of the side branches, but not bad for a noob.
Oh yeah it was in a hempy with OC+ too. 
Can't wait for the hps for the 12/12 I'll trim most of the side branches since the light will be able to penetrate all of the cola. Thanks to DocBud and his journals awhile ago on this deal. 
