# HPS Light Question



## Badali05 (Oct 5, 2006)

I recently ordered a 400W HPS/MH Switchable system off ebay unfortunatly, it only came with an HPS bulb and not an HPS/MH conversion bulb.  Seeing as how I sent almost all of my money on the complete system I don't have any money left to get a HPS/MH conversion bulb.

Just to clarify, I have read quite a bit regarding MH/HPS lighting systems.  I do know that the MH light is used during vegetative and the HPS is typically used during the flowering period.  My question is since I dont have enough money to get a conversion bulb, can I just use my HPS light during the vegetative period as well as the flowering period, or will that not work?


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## Tonto (Oct 6, 2006)

Yeah, you can use the HPS for the whole grow....
You can use anything for the whole grow!! Jusy get different results. I'm currently on day 19 of my MH/CFL only flowering cycle....
As for a conversion light, I would think that it's not a single light that switches form MH to HPS, but rather a switch or changing wiring slightly and using a completely different bulb.....
Good luck with the grow... where did you get the light from? Perhaps you have a link to a similar product? Do you have anything growing right now? Do you have any pics?


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## Canso (Oct 6, 2006)

from what i understand.
You can use a regular MH bulb and just switch the balast to MH.
A MH bulb is under $40



conversion bulbs or for using HPS balasts.


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## Badali05 (Oct 6, 2006)

Good luck with the grow... where did you get the light from? Perhaps you have a link to a similar product? Do you have anything growing right now? Do you have any pics? :D[/quote said:
			
		

> I got it off of ebay for $120 including shipping, it is on it's way.  Unfortunatly, I cannot find a link to anything resembling the unit I got.  Basically, it is an HPS/MH Switchable Ballast.  It includes ballast, 400W HPS bulb, and a reflector.  Currently, I have a few plants started which are about 2 weeks old and I will see if I can't take some pics this weekend and get them posted.  Btw I am pretty sure that a 400W bulb was prime for my growing area which is 3.5' tall by 4'long, is this true, or should I have gotten a lower wattage bulb?


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## Mutt (Oct 6, 2006)

the target is 50W per sq.ft.
your at 14 sq.ft. (3.5'X4') so 400/14=28.5W per sq.ft.
I would consider putting floro sidelighting to helps with the dark areas that will be around the edges. IMHO


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## Hick (Oct 6, 2006)

length X width= sq/ft...you should be looking for 50 watts per sq/ft
3 1/2 ft tall?...considered the light will consume approximatly 1 foot and the pots 1 foot, without a "cooled hood" the plants need to be _at least_ 1 foot away from the HPS, where are your plants going to grow?..
You need more room my friend.


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## Dr.GreenThumb (Oct 6, 2006)

My grow was done under a HPS bulb for the entire time, I wanted to know the results without using a MH bulb. I actually perfered the HPS bulb over the MH. http://www.marijuanapassion.com/forum/showthread.php?t=4041


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