What size HPS do you recommend for me?

Hi guys, I originally decided to go with CFL's for reduced heat and cost savings but they just ARE NOT efficient!!

Worked out the lumens of a 400w of CFL's vs a HPS and there is just no comparison between the two...

I am working with a 4ft x 3ft box and a ~8ft height which I can reduce.

I am planning a SOG grow with 4 plants per sq ft. My first grow will be about 30 plants though and not utilizing all my space. But what would you recommend?
I was thinking either 1 400w or 1 600w HPS , will that fit my size? or should I get two lower wattage lights.

And is the heat THAT significant? being stealthy is obviously a requirement. At the moment my grow room is a bit on the cool side, its 70deg F (21deg C). So the heat may offset it a bit ...
Its winter here also and I have a small window right by my grow box for fresh COLD air and also its close for my exhaust.

Opinions? And what should I look for when buying a kit or bulbs?

Sorry for the long read but I appreciate any input!

If you have proper ventilation I would go with a 600 watt light because a 400 you won't be getting the most out of your footprint. Though it's true during the winter cooling is really not difficult but if it gets hot during the summer, your grow box will become an oven without good cool air exchange.

Basically, if you can vent a 600 it'd work very well in that space, but a 400 would also do pretty well with less heat, at the sacrifice of an optimal footprint.

What morange said

3.414BTUs per 1 watt, so 600w = 2048.4BTU's

You can use that to compare to some heaters you have at home to see roughly what the heat output would be like.

As for what you should buy, if you've got the money go for an electric UL certified ballast (quantum) and get some digilux/hortilux bulbs. The cheaper alternative would be a lesser quality electronic ballast or magnetic ballast and cheaper bulbs.

^ Im hoping to NOT be growing during the hot summer months, OR I may kick back to cfls ...

Do you think a 400w HPS along with a few 23-40W CFL's will be a better option in terms of reduced heat vs a 600W HPS?

Regardless I plan on running a few 6500k CFL's with my HPS to give my plants a range of light spectrum.

^ Im hoping to NOT be growing during the hot summer months, OR I may kick back to cfls ...

Do you think a 400w HPS along with a few 23-40W CFL's will be a better option in terms of reduced heat vs a 600W HPS?

Regardless I plan on running a few 6500k CFL's with my HPS to give my plants a range of light spectrum.

No, get the 600w HPS.

What morange said

3.414BTUs per 1 watt, so 600w = 2048.4BTU's

You can use that to compare to some heaters you have at home to see roughly what the heat output would be like.

As for what you should buy, if you've got the money go for an electric UL certified ballast (quantum) and get some digilux/hortilux bulbs. The cheaper alternative would be a lesser quality electronic ballast or magnetic ballast and cheaper bulbs.

Sorry I didnt even see your reply! Thanks for the reply,
Ill try to compare it to my propane heater I use in my garage when I work on my cars/bike.

But what kind of heat difference do you guys think there will be in 600w HPS vs 6-750W in CFL's, if there isnt a HUGE difference than I think I found my answer..

One last thing to mention, I checked my bills and it turns out they change the pricing and there is a OFF PEAK rate of 5.9c /kwh between 7pm-7am .. I know that the heat WILL BE noticeable say at 6am on a cold morning, should a 600w be something that I should worry about for getting caught? If not it may be a bit better idea to run my lights during the mid-peak hours and pay a bit more but reduce chances of ambiguity and getting caught ..

wow you guys reply quick! I keep getting replies when im replying to my own thread

Alright I think I may go for a 600w HPS, going to do research on prices and what not now..

Thanks a ton guys!

any extra input will still be appreciated!

Granny's got the study!


The Effect of Electrical Lighting Power and Irradiance on Indoor-Grown Cannabis Potency and Yield. (abst – 2011) The Effect of Electrical Lighting Power and I... [J Forensic Sci. 2011] - PubMed - NCBI

Sorry I didnt even see your reply! Thanks for the reply,
Ill try to compare it to my propane heater I use in my garage when I work on my cars/bike.

But what kind of heat difference do you guys think there will be in 600w HPS vs 6-750W in CFL's, if there isnt a HUGE difference than I think I found my answer..

One last thing to mention, I checked my bills and it turns out they change the pricing and there is a OFF PEAK rate of 5.9c /kwh between 7pm-7am .. I know that the heat WILL BE noticeable say at 6am on a cold morning, should a 600w be something that I should worry about for getting caught? If not it may be a bit better idea to run my lights during the mid-peak hours and pay a bit more but reduce chances of ambiguity and getting caught ..

I mean if you got 3 or 4, 200w sunblaster CFL's (which have the highest lumen output), the heat would be less than that of a HPS - but the CFL will produce comparably less lux output than the HPS. (14,000 lumens for 200W cfl, vs maybe 45,000 for a 400w HPS)

So it's just not worth it, you can easily vent 600w and redistribute the heat throughout your house, and it will be easily to deal with. Cluttering your entire space with a maze of CFL's isn't a great idea.

As for the power consumption, 600w isn't really anything to be worried about. You could easily cut consumption from other areas to help with the difference. Stop leaving unused lights on, turn off tv's etc etc. My space heater uses 1025w, and I leave it on for hours each day. It's nothing to be worried about.

Granny's got the study!


The Effect of Electrical Lighting Power and Irradiance on Indoor-Grown Cannabis Potency and Yield. (abst – 2011) The Effect of Electrical Lighting Power and I... [J Forensic Sci. 2011] - PubMed - NCBI

THANKS!

I JUST found the FULL article through my schools data base. I have the PDF, aynone want me to post it up? Ill skim through now and see how useful it is

I mean if you got 3 or 4, 200w sunblaster CFL's (which have the highest lumen output), the heat would be less than that of a HPS - but the CFL will produce comparably less lux output than the HPS. (14,000 lumens for 200W cfl, vs maybe 45,000 for a 400w HPS)

So it's just not worth it, you can easily vent 600w and redistribute the heat throughout your house, and it will be easily to deal with. Cluttering your entire space with a maze of CFL's isn't a great idea.

As for the power consumption, 600w isn't really anything to be worried about. You could easily cut consumption from other areas to help with the difference. Stop leaving unused lights on, turn off tv's etc etc. My space heater uses 1025w, and I leave it on for hours each day. It's nothing to be worried about.

My exact thoughts, its just NOT efficient. And your right I can redistribute it through my house for heat so I can save on heating costs!! :hello:

And I think a 600w HPS is perfect for me! , BUT the only downfall is the cost ... but Im sure it will pay it self off within time.

My exact thoughts, its just NOT efficient. And your right I can redistribute it through my house for heat so I can save on heating costs!! :hello:

And I think a 600w HPS is perfect for me! , BUT the only downfall is the cost ... but Im sure it will pay it self off within time.

If you make sure to take the time to give your plants the best environment you can give them, it will pay it's self off after one harvest compared to what you'd have to pay street value for what you'll get. In fact I don't think I've had a grow where I didn't harvest at least 2x the 'value' of my setup, saves so much money. Especially if you live in a place like I do, where weed is really expensive.

Weksos,did you actually try a grow using cfls,to find out they were not efficient???..if so,what did you have?....Im thinkin of putting some cfls together n see how it goes...curious about your setup.if you tried it yet.

If you make sure to take the time to give your plants the best environment you can give them, it will pay it's self off after one harvest compared to what you'd have to pay street value for what you'll get. In fact I don't think I've had a grow where I didn't harvest at least 2x the 'value' of my setup, saves so much money. Especially if you live in a place like I do, where weed is really expensive.

I like to do things right the first time around! Or at least get as much info as I can to attempt to do things right.
And I feel you for sure, marijuana is pretty much a cash crop, if you have time on your hands, that can be converted to money in terms of either distributing your product OR money you SAVE which will remain in your wallet!

Weksos,did you actually try a grow using cfls,to find out they were not efficient???..if so,what did you have?....Im thinkin of putting some cfls together n see how it goes...curious about your setup.if you tried it yet.

And no this is my first grow, at the moment I am just vegging with CFL's, but after crunching numbers and figures, I realized that CFL's just cant compare with HPS, which is why I asked the forum, which only backed up my original idea. I dont know why but here, a 40w CFL from home depot runs about 12bucks a piece! Either way when i worked it out, running 600w of CFL will give you almost half of what the SAME amount of watt's a HPS will give.
When trying to keep cost low, you want to get MAX efficiency or else it will only cost you $$. Im sure the CFL grow would be successful but it just wont be able to compare to the HPS lighting.

For very small grows or single plant grows, cfls do the job, but yeah they cannot compare to HID lighting. I upgraded right after my first grow, I put a lot of effort into it but the harvest was small and the buds were loose, so I went to HID lighting and have not regretted it in terms of cost/time etc.

How about a pair of 400w, each covers a 2x3 area, that's 67w per sq foot of HID...

For very small grows or single plant grows, cfls do the job, but yeah they cannot compare to HID lighting. I upgraded right after my first grow, I put a lot of effort into it but the harvest was small and the buds were loose, so I went to HID lighting and have not regretted it in terms of cost/time etc.

Good thing I asked this forum for opinions, or else I wouldve done EXACTLY what you've done. Always debated between CFL's vs HPS ... gotta do it right the first time! Thanks to your responses I've definitely decided on HPS.

How about a pair of 400w, each covers a 2x3 area, that's 67w per sq foot of HID...

That was my next issue, I was going to ask if I should stick with 1 600w or two smaller wattage lights.

Do you know what kind of coverage a 600w can cover? And how far do you set them from your plants? Because I may have to redesign my grow box to implement hanging HPS lights.

Im looking at a few 600w kits on ebay going for ~$200, and a few hydro stores have them for 350-400 for the complete kit. So I may consider buying online since hydro stores here seem to jack up the prices.

Do you know what kind of coverage a 600w can cover? And how far do you set them from your plants? Because I may have to redesign my grow box to implement hanging HPS lights.

Im looking at a few 600w kits on ebay going for ~$200, and a few hydro stores have them for 350-400 for the complete kit. So I may consider buying online since hydro stores here seem to jack up the prices.

600w is like 3x3', for the next question refer to this:

http://i.imgur.com/zcibH.jpg/

You've got a few options, and i'd just go with whichever is most cost effective. Some ideas: buy 2 ballasts of lesser wattage, or buy a lumatek dual 600w for example. I'd either setup one 600 watt or get a 1000w for the future and turn it down to 75% (1kw quantum is $220 rather than buying 2x 400w), and get a flipbox so you can run 2 hoods, non-simultaneously so it looks better on for your power consumption.

Flipbox by Powerbox | Grow Light Accessories

Edited by s7exiled, 08 January 2012 - 07:36 AM.

QUESTION 3 plant flow setup up. Seedlings now under 4 cfl 27 w daylight spec. In a a week o so goin to throw these ladies under a 400w mh. Now my question keep the cfls or only run wit the mh? Had success before with only mh but curious about usin both.... thanx

I'd get a 600w with an adjustable ballast...then you can turn it down in the summer or if it gets too hot