to go 250w or 400w...decisions decisions

[THENGINEER]

ok...so im debating whether or not to go 250 or 400w hps. Before you say go 400w...here me out for a second.

Cost wise, they are both the same in my situation. the problem lies with my ventilation.

All I have for Vent is the following

1 squirl cage type fan. Was salvaged from a hood range. Has actually 2 Cages and 1 motor...so really like 2 small squirl fans. no idea on the cfm rating. like 100cfm?
2 bathroom fans. Each good for probably 50 cfm..the cheap ones.
1 fan to circulate the air inside

I really cant afford much else since the budget wont let me.

Now...the grow room will be in my attic. What im wondering is, since being in the attic, and it being fall/winter when this goes together (mid october)...will that ventilation be sufficient to cool a 400watter? After Christmas, I will be able to upgrade my ventilation to whatever is necessary (most likely a 6 or 8 inch vortex inline type fan...400+ cfm rating)...but until then...only what i posted i will have.

I have never dealt with a HPS light before, only cfl. So i am wondering, with my conditions...is the 400watter doable? The grow area will be apx 2.5*2.5*5 feet...if the 250 watter is used....itll be 2*2*5 feet

Thanks for the help!!

I forgot to add the following (was thinking about it when i went to bed)

1. While this will be in an attic...The grow will be in a box (2x4's and plywood)
2. The light will have a aircooled hood or one of those cool tubes. Probably the air cooled hood since it will be easier for me to make that and cheaper (have glass and sheet metal lying around...not a bake around thing)

Good idea on the vertical grow...but i only want to have 2-4 plants in case things turns for the worst to have minimal legal issues. Ive never done nor seen a vertical grow. I was thinking of doing lst'ing mixed with some scrog or do reverse scrog

Also...do not worry about summer heat. I typically either don't grow in the summer indoors since you have the outdoors, and if i do grow indoors, money wont be so tight so either ill upgrade the fan (well, gonna do that no matter what), or downsize the light

 

[icon]

maybe you can get the 400w and then get a turbo fan for $10 it has 3 settings on low its powerful i didnt get a reducer but made one out of the bag it came in & works very well. it keeps my 400w cool on low.


also check out this thread on it


http://www.icmag.com/ic/showthread.php?t=44574

 

[Guest]

do a vertical scrog and 250. You should be able to yield similar to a 400 horizontal if you use the 250 verticaly. Now if you do the 400 verticaly, that would be the best.

There is a thread out there that shows pics of a guy named g_man that's on a CZ site that did 148 or so grams with a 150hps. Do the math, if you know what your doing, 250 would do you good.

 

[Guest]

All I know is I went with a 400w and now wish I had gone with a 600w. But Dasme is right, if you know what you're doing you can pull some really good harvests using almost any wattage.

The biggest issue I think you'll encounter is summer heat in the attic. In the winter I think you'll be fine. The main reason is the ambient temps in the winter. A smaller CFM fan might not be moving as much air, but the fresh air it's bringing in will be cold cold cold...keeping everything in line.

Get a huge fan with great CFM, but allow the ambient temps to get high, it wont really matter. The fan will move a lot of air but the air it brings in will be hot hot hot, not helping at all.

 

[Siddartha]

Or you could run 2 150 watters, they're mad cheap and seem good for scrog based on penetration and intensity.

 

[THENGINEER]

I forgot to add the following (was thinking about it when i went to bed)

1. While this will be in an attic...The grow will be in a box (2x4's and plywood)
2. The light will have a aircooled hood or one of those cool tubes. Probably the air cooled hood since it will be easier for me to make that and cheaper (have glass and sheet metal lying around...not a bake around thing)

Good idea on the vertical grow...but i only want to have 2-4 plants in case things turns for the worst to have minimal legal issues. Ive never done nor seen a vertical grow. I was thinking of doing lst'ing mixed with some scrog or do reverse scrog

 

[Guest]

Link to G_MAN's incredible grow:
https://grower.cz/forum/showthread.php?threadid=11193

http://www.icmag.com/ic/showthread.php?t=20729&page=10&pp=15

I get the feeling that you will bug out when you see what this guy has done.
And all with a 150. Im not trying to be bossy, but 250 will king your situation. Between plant numbers, and heat that's all you need. TheGhost pulled 7zs off a 250 scrog with two or three plants if I remember correctly...

http://www.icmag.com/ic/showthread.php?t=31172

Das.

 

[THENGINEER]

omg i cant decide!!! lol the two light setups will cost me essentially the same, give or take 5 bucks.

I want the 400....im just worried that either i wont be able to cool it...but i think i should in my attice...and number 2...if it warms up the area too much...im more worried about the snow melting on the roof....that would be a huge heat issue with the po po's.

Anyone know the heat output of the two?? My attic is about 200 cubic feet...Im wondering how many degrees it will raise the temp...both the 400 and the 250

 

[THENGINEER]

alright...looks like i went with the 250 for stealth reasons.

 

[THENGINEER]

I have a bathroom squirlcage type fan that is rated for 120cfm and a aircooled hood. should this be enough for venting and to keep heat low?? I can seal the 250w light if need be aswell with glass. im trying to get by with little so noise wont be so much if a problem

 

[george j warner]

hey man im used to both 250 and 400watters ..personally for that space go with the 250 and make a hydroponic system to fit the space.. your get more yeild .

ive grown under 2 x 250 HPS in a space that was far to big for the lights and the plants were fine use the hole space for plants ...
manufactures say a 250 is for a space 2-6 ft squared but they push a little more . it will be fine in the 2.5ft x 2.5ft space . a 400 would be optimum but the extra heat will be have to be vented away with a grow fan .... ive cooled 250's with multiple 120mm computer fans !

next thing to buy is a cheap 4" grow fan!

pic below was a 250 in a space 3' x 2.2'
super silver haze







these were flowering under a 250 to 5weeks then in a room under 1000.for last 3 weeks but the yeild was all 250 the resin was 1k .
great white shark

 

[george j warner]

sorry that yellow one was the big room with the 2x 250 3' x 3' for 1 x 250
super silver haze and dutch passion blueberry