What Watt HPS/MH Should I Use?

[Qwerg]

I have a 400w HPS and 400w MH but I fell like its not necessary to have that much light for 3 plants. I might bust out the 400w HPS for flowering but thats it. So whats better for my sistuation, I want 3 small-mid sized blants with a good yield. 150w, 200w, 250w, or what? Thank you!

Note: So far I'm going to grow in soil, maybe I'll take the hood off my AG Pro 200 and use the HIDs.

 

[kyoinidaho]

just give them both in both stages, definately enough for 3 plants

 

[Qwerg]

FOr reasons I can;t explain, lets just say there's an issue with running something with the name 400 Watts on it.

 

[fish601]

why not use the 400w are you trying to save on electricity?

 

[Qwerg]

sve on electricity...i have a feeling this light will run the bill up quite a bit

 

[fish601]

i try to make sure i turn off unused lights in my house also i am trading out my 100w lightbulbs with 26w cfl so when i do have lights on its not using as much electricity. Its also why i grow most outdoors

 

[NWGREEN]

sve on electricity...i have a feeling this light will run the bill up quite a bit

Your bill shouldn't go up to much. If your running a 400 watt HPS 12 hrs on, it should only cost you around $45 a month. Give or take a little. Hope that helps . Happy Growing !!!

 

[fish601]

$45 more a month is alot when you are all ready paying an overpriced bill.....but in long run it will save money if your grow goes good

 

[Qwerg]

Well I have to veg so It would be on for 18 hours. Plus $45 is alot. Would 150w not be good enough to get a great yield from 2-3 plants?

 

[Darkuser]

At $0.10 kwh on 12/12, a 400 watt light will cost $14.4 a month.

 

[Qwerg]

What's the formula for that? How about 18 hours?

 

[Darkuser]

hours a day*days in a month=total hours used
total hours used*kilowatts=kilowatt hours used
kilowatt hours used*the amount your electric company charges for kwh (kilowatt an hour)

18*30=540
540*0.4=216
216*0.10=21.6

$21.6 a month

 

[Darkuser]

Figure out how much your being charged on your bill for kwh. I am charged 6-7 cents a kwh. Some places charge as much as 14 cents. It all depends on where you live.

 

[fish601]

At $0.10 kwh on 12/12, a 400 watt light will cost $14.4 a month.

that looks alot better than the $45 someone said

 

[Darkuser]

that looks alot better than the $45 someone said

A ton of people have a completely wrong idea of how much power costs.

A good gaming machine computer uses 600w easily not counting the monitor, and mine is running 24/7 pretty much. Small 5200btu AC in my living room running 24/7 is 500w. Household appliances running all the time, etc.

All before you consider what your op uses. Most closet grows will barely notice.

 

[Qwerg]

hey thanks for the formula man. I still dont know if 150w would be not enough for 2 or 3 plants. Maybe 200w or 250w? I just really don't want to run 400w lights.

Infact the only reason I have 400w lights, is because I got them with my purchase for free.

 

[Darkuser]

It all depends on how big you intend to go. Small lights don't have much light penetration. If you intend to keep them fairly small or train them horizontally, 200w can be great.

 

[fish601]

a 250w hps will work for a 3x3 foot area which you can fit 4 plants easy
may i ask what you bought to get that for free?

 

[Qwerg]

I bought the lighting system from a friend of mine. He threw the lights in with it.

 

[ThomasJeffersonDidit]

The general idea behind these formulas are dead on. They are right a 400w is really not going to cost you enough for you to even recognize an increase. And while its always a good idea to start small, anything smaller than a 400w is almost deemed worthless if you ever plan on doing more. Trust me, you'll end up wanting to do more eventually... lol