dumb question?

440 lumens per square foot??? is that right??? thats terrible... for the extra 3 bucks I might as well get a 400 W HPS than right??? I know they get hot as fuck... but how hot as fuck... what type of ventilation will I need to do???
 
wow wow wow... I was just looking... and a 400 W HPS emits 55,000 lumens... and they can be used alone in spaces bigger than mine... So... Do you mean 700 or 800 lumens perfoot???
 
Dude, your math sucks. You take the total lumen output and divide it by your total square footage. 55000/(3x3) = which Im guessing is 6000 or so, which is more than enough to produce good ganj. 100000 lumens being ideal and 3000 being the absolute fucking minimum.
 
Get some oscillating fans too, those pc fans arent going to cut it.

Oh yeah, that lumen calculation is for a perfect world, you're gonna lose at least 10% if not more. Blah blah light diffusion yadda yadda reflective walls not perfect yackety-scmackity.
 
but why is my space only 3x3??? dosnt it need to be the lenghth plus the width times the hight???
or lenghth times width times hight... I rememeber alot of math teacher saying that... dont know why... but they said it...
I dont know... So you are saying the 400 W???

How much ventilation will I need to addd??
 
yakity yakity??? hmm sounds complicate... I have one of thoes tall skinny circular fans in there... its pretty powerfull but its just blowing air around the room...
 
You need to multiply all three for CUBIC feet, you multiply length and width for SQUARE feet, which is what we need. Good grief what are they teaching in schools these days... did they teach you god created the world in seven days too?

As for ventilation more is better, but you're going to have to figure it out yourself. Just get a thermometer and make sure it stays at 70 to 80 (with the lights on).
 
Definitely get the hps for flowering if you can afford it and I would consider t5ho for vegging.

you need 2000 lumens per square foot to veg

and I would say atleast 5000 lumens per square foot to flower

personally I am running at around 3000 lumens for vegging and 7000 for flowering



-pot
 
after reading in the grow FAQ I came to the conclusion that my room is 45 square feet and yea... it says for ventilation you want to have 2-5 times the CFM cubic feet per minute. that the air moves... or something like this... So my fans say the move 85 CFM and so I have 2... SO 2 more would be more than enough ventilation?????
 
man I don't know where you learned math but you should take a few brush up courses.

Square feet = length x width
Cubic feet: length x width x height

cf of 3x3x5 would be 45
sf of 3x3x5 would be 9

85x2 would work but a stanley blower fan from walmart @ 39.99 would be stunning at ~ 2300 cfm attached to your hps light and a diy activated carbon filter which you could build for less than $10 for smell venting.


-pot
 
what is a stanly blower fan?
how big is it?
The HPS hood I want to buy dosnt have that thing where you can do it up and make it blow the hotnes right out...
 
then go with this inexpensive reflector and find a way to mount some plexiglass in there.

Or if you don't mind spending a little extra dough go with one that is already designed for that. Did you already order the ballast reflector and bulb?

Stanley is a brand- and that particular fan is a gem because it is very inexpensive and blows large amounts of air aka perfect for exhaust.


-pot
 
if you wanted to go with a digital switchable ballast you could get mh bulb for vegging and then hps bulb for flowering and utilize that the whole way through- if you were able to address the heat as with that stanley fan and a good air coolable reflector you would have one nice system with some tight compact buds.


-pot
 
haha...
I know what stanleys is... But the way you called it a blower fan... made me think of it as somthing... that... was not fan like... and I was thinking of like a leaf blower... in my room...
Is it just a regular fan that stanleys thinks they can patent???
I didn't order the light yet... I'm still trying to moe a few things over befor I order it...
It says I'd have to pay an extra 45 bucks to make it compatible for MH and HPS... and they have lightbulbs that cost 25 bucks extra too... dont know why...
that reflector is half the price of the light... I will eventualy buy one of thoes reflectors... but right now. I barley have enough for the HPS? lets just say?
 
tckfui said:
wow didn't even see the 400 W HPS... My ventilation isn't that great... just 2 PC fans... the biggest ones I could find... one intake outake... and a fan blowing on my plant...
I'm planing on only flowering in there... maybe veging alittle bit... but I have a seperate space for that... so if my space is 5x5x3 lets say... that means its 75 square feet?????? so if a 350 watt is 33,000 lumens that means... hold on... this is going to take awhile...
Click to expand...

lets stop for a minute and clear up a few things before you decide which light to buy. To start with, the post above, about about how many lumens are needed for the different stages of growth is very accurate. You need 2 Different types of light for the 2 Different stages of growth. You need blue for vegging and red for flowering. This means you'll need 2 Different bulbs for that HPS light or 1 Full Spectrum bulb, if its the only light you plan on using. Next lets address how much light you'll need. Square footage is the length x width of the area youre using, NOT lenth x width x height. Thats cubic feet. Assuming your measurements mean 5'w x 3'l x 5'h= 15sq/ft. This is way more area than a 250W or even a 400W HPS is recommended to light. A 250W will light an area about 2x3 and a 400W about 3x4. If i were you, and i had 2 seperate areas for veging and flowering, i'd keep the fluorex for veging, and either buy a 600W HPS for flowering in an area that big, OR make a smaller area and get a 250W HPS. There will be much less heat and engineering involved when doing it with a smaller light. You should be able to grow 4-6 plants under 250W and get really great buds. Assuming the soil,water, and environment are good.
 
tckfui said:
but why is my space only 3x3??? dosnt it need to be the lenghth plus the width times the hight???
or lenghth times width times hight... I rememeber alot of math teacher saying that... dont know why... but they said it...
I dont know... So you are saying the 400 W???

How much ventilation will I need to addd??
Click to expand...
and how long ago were you in math class. Memory might be going a bit lol
 
I dont know how long ago it was... that would involve me doing more math... I dont know if my mind can take it... yea your right I should keep the florex for veging... But right now I dont have the money... but when I do I definetly will do that... CFLs are working alright but not as good as I'd like to see...
I've seen 400W HPS used to flower in rooms 3 times the size of mine... couldnt I get away with 400 W???
I'm afraid of the heat... and the heat and fire... and the fact that if you get them wet they blow up... because I'm always getting water all over the place... even on the ceeling?
 
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