New Grower HPS Dual 400w for closet with 170x100x55 ?

[mmoloch]

Hi

In the coming days I will order everything I need for my first indoor grow but I have some questions regarding the light kit, my closet has 170x100x55cm but do not know what is the most appropriate light, I want to grow six auto seeds at a time (4 indica and 2 sativa).

My idea is to buy a full 400w kit (ETI, Agrolite HPS gro&flo, reflector, cooltube 120-490 and extrator 190 m³/h)...

... my question is, this full light kit is suitable for my closet or is too potent?


Besides the cooltube extractor will have 5 pc fan's for air in (3x180mm silverstone and 2x140mm scythe kaze) and 6 pc fan's for air out (6x120mm coolink swif2), if necessary I still have more than 10 pc fan's of good quality (lian li, silenx and silverstone).

Best regards

 

[Muddy]

The general rule of thumb for HPS lights is 50 watts per square foot in veg and 60 in flower. To light the whole closet you would need about 1,100 watts total and you would have enough space to grow about 12 plants. Since you only want to grow 6 you would need a 600 watt light. If you were to expand later on you could add a second 600 watter and fill the whole closet. HPS light put off a lot of heat and it could become an issue. With a cool tube reflector you might be better off drawing your air from outside the closet, through the cool tube and then exhausted into another room or outdoors. For air exchange inside the closet I would recommend ditching the PC fan idea and going with an inline fan and a passive intake. Have you considered using either T5 or LED lights instead of the HPS? There lower heat output is a lot easier to manage that the high heat from HPS lights.

 

[thetreeman]

Also light height management might be tough with sativa and indica with a single light, better to do a full batch of one variety and then switch...

 

[mmoloch]

The LEDs are too expensive, the reviews that I have read the HPS are the most recommended that's why I think I'll buy the HPS with cooltube and extrator but probably I'll have to invest in better extraction.

The 400w kits I've been seeing have option to choose a reflector and a Cooltube but I can also choose a Cooltube Reflector, what is the best option?

wow 12 plants in my space?!... I think there may be some confusion with the measures, will convert the measures of my closet to "inches":

39.370 inches x 20.685 inches x 66.946 inches height


If my closet has space for 12 plants is likely that I do grow 10 plants at a time but unfortunately I think there may be some confusion with the measures...


My idea was to choose Sativa strains with low structure because of the light height but maybe it is best to have only one strain at a time or I can choose 2 or 3 types of Indica strains?

 

[Muddy]

You have your measurements in the wrong order, which is where the confusion is. It's always L x W x H. You had it L x H x W. For the sake of this discussion we aren't concerned about the height, only the length and width. So you actually have about 39" x 22" or 6 square feet. So yes, a 400 watt HPS would be enough for that space. That would be enough for 4-6 plants, depending on the size of the strains you choose to grow.

Something to consider when comparing HPS to LEDs is the cost of replacement bulbs and electric usage. Most HPS bulbs have a rated life of about 20k hours. Their output drops drastically at about 80% of their rated life and should be changed at that point, so at 16k hours. Growing on a 20/4 schedule that's about 2.5 years. Many growers change them about every 2 years. The cost of a good replacement bulb is about $100. So add $300 to the cost of your HPS system. LEDs use about 30% less electricity than HPS, so also factor that into the cost of the HPS. Over the 5 year rated life of most LEDs they are cheaper to use than HPS. Yes, the upfront cost is more but overall they will save you money plus you won't have to deal with the heat issues associated with HPS.