Opinions/Advice needed for my first grow room design

[TX-Skydiver]

I have a roughly 3' 6" x 6' closet with an 8' ceiling that I am converting to a grow room. My plan is this:

Walls will be covered with Mylar for light reflection
160 cfm supply air fan from climate controlled bedroom through wall into closet near the floor
190 cfm centrifugal exhaust fan with carbon filter and variable speed controller in the ceiling, venting into the attic of a two story house.
Digital thermometer/hygrometer

I am planning on using CFL's for the first few grows, but am not quite sure how many I would need for a 6 plant grow in this sized space?? Plan was 32 watt 6500k for veg and 26 watt 2700k for flowering. Am I going to need a shit ton of bulbs this size? Or would I be better off using the 250 watt bigger bulbs? I have done quite a bit of research, but there are so many sites that have varying opinions.

First two grows will be Blue Mystic and Bubblelicious from Nirvana.

Any input/opinions on my closet setup and lighting would be greatly appreciated.

 

[Fuzzy Duck]

Set up looks pretty fine to me the fans 160/190 cfm look pretty alright for that space... i might push for a larger exhaust fan tho but all depends on how well the temp is controlled ultimately & this really relates to amount of bulbs (CFL) or size of HPS/MH used.


By the time you've got a suitable amount of cfl's in their & would expect a dozen or so ya be near running the same wattage as a 400w HPS !

Unfortunaly whilst cfls do produce bud they really do lack in the red spectrum of light & HPS will certainly out perform the cfls yield wise


You could safely get away with a 400w HPS in your area & current fan cfm i expect, using 600w HPS ya more likely need an air cooled hood/reflector to help tame temp as the bigger wattage bulbs used the great heat out put generated.

Air cooled hoods can easy be rigged up to exhaust fan carbon filter > length of ducting > air cooled hood > length of ducting > exhaust fan > out take vent... & would be incline to use a larger exhaust fan for this purpose.


I've grown both blue mystic & bubblelicious by Nirvana myself, bubblelicious is slightly prone to effects of over feeding i found with Blue Mystic being pretty fine all the way through.

 

[TX-Skydiver]

Thanks for the reply!

I plan on eventually using an HPS/MH combo, but wanted to get a few successful grows under my belt first and also was concerned with the heat issue from the HPS lights. I just figured it may be easier to get my feet wet with a CFL set up?

Do you think a 400W HPS setup would be sufficient for 6 plants in that space?

I still may go HPS/MH as I haven't built the lighting setup yet, but I have everything else already so I don't want to have to buy bigger fans at this point if I need a 600W HPS setup. Would I need a separate fan for a cooled light hood, or just route my current one through the hood with duct and use it as the primary exhaust fan as well?

Thanks again!

 

[TanR]

Hi TX-Skydiver,

Welcome to 420 Magazine and the community of like minded folks that gathers here!

Nice sounding setup - congrats. Two quick thoughts for your consideration.

Yes, I beleive you will need a shit ton of 32 watt cfl lights for six plants. You might investigate a couple T5 VHO flourescent lights as a more economical solution.

Since your venting into the attic of a two story house, I wonder if the carbon filter is really a necessity. I think the odor from 6 plants woud disperse pretty thoroughly into the air in the attic and would not be noticable to anyone outside the house. I wouldn't anticipate being able to detect it indoors either.

 

[TX-Skydiver]

Hi TanR and thanks for the welcome!

My main concern was odor inside the house, hence the carbon filter idea.

I had looked at a T5 system, 4' ballast with 8 bulbs, 40K Lumens using 6500K blues and 3000K Reds. Opinions on that setup? And would one of those be enough?

The lighting is really the only thing I'm still pretty confused about, and mainly just confused about how much of each type of light I would need.

 

[Graytail]

Ah, the CFL question ...

CFLs are absolutely fabulous for sprouting and the first month or so of veg, but when it comes to flowering, they just don't end up being a rational choice.

There are rough rules of thumb you can follow - 50 watts per square foot for instance. You have quite a bit of space, but only 6 plants, so we can calculate for those. Each plant should be allocated roughly 1 1/2 sq ft of space, depending on how long you've vegged them, so that's at least 9 sq ft or so = 450 watts. You could get by with 30 watts per sq ft as a minimum, and that's still 270 watts.

The smaller bulbs are more efficient. I went with 23 watters and built two rigs - one with 21 bulbs for 483 watts and another with 10 bulbs for 230 watts. It seemed like a good idea at the time - y'know cheap and easy. But by the time I had bought sockets and bulbs and something to hold it all together, I had spent more than the cost of a 600 watt HID. So, I snagged one on ebay for 139 shipped and now only use the CFLs for veg. Now I can't even imagine trying to flower 9 plants under CFLs. Sure, you can do it, but what's the point? It takes longer, you get smaller buds and it costs more.

A 250, 400, or 600 watt HID simply makes more sense for the relatively large space you have and the ventilation plans you have. CFLs are a smart substitute when you're growing in a small box, or have no way to vent heat.

I'd get a 600 watt HID. They're the most efficient, and the adjustable ballast lets you turn it down to 300 watts if you want.

[Edit} hiyas, TanR!

 

[TX-Skydiver]

Thanks Graytail

I'm really re-thinking the CFL's now, especially in regards to the yield. Doesn't seem much easier or cheaper to warrant negating a lot of my yield.

600W HID it is

 

[TanR]

Tex,

Gotcha on the odor. Certainly your call. Food for thought - your plants won't emit much smell at all for a couple months if growing in soil so that might be added later.

Getting specific on lighting suggestions might require additional information. I assumed from your alias that your in Texas. I live in a state neighboring TX, that also gets pretty warm in the summer and fall and perhaps incorrectly assumed you wished to use CFL's or some type of flourescent to avoid the heat issues created by high intensity discharge lighting. I do believe one 4' -8 bulb T5 would provide enough light for you to grow some decent buds.

Graytail (Hiya back at ya!) offers good advice on evaluating your lighting options and I will offer that I too am partial to switchable HID lighting. I was thinking the T5 for you though as your space is so much longer than it is deep. Most relectors on HID lighting tend to light in a squarish or only slightly rectangular pattern. You've got six feet of width and I thought a longer bulb and reflector would allow you to utilize more of that floor space.

Lots of info and analysis on here about the correct colors but us casual home growers, an easy rule of thumb is that during a plants vegatative period you want higher Kelvin numbers 6000 or higher. During the flowering period you want lower numbers 3000 or ideally 2700K. And the overarching rule on lighting is "The more the merrier!".

 

[Fuzzy Duck]

Thanks for the reply!

I plan on eventually using an HPS/MH combo, but wanted to get a few successful grows under my belt first and also was concerned with the heat issue from the HPS lights. I just figured it may be easier to get my feet wet with a CFL set up?

Each CFL produces heat & that builds up per bulb !

Do you think a 400W HPS setup would be sufficient for 6 plants in that space?

No not really a 400w will cover aprox 3' by 3' and at a push 4' by 4' depending on hanging height ?

Then we must think about the square law of light effect... the greater the hanging height the less light energy the plant receives this directly effects yield (light energy diminish over distance) so more or less you got to choose a right size bulb for area or multiple bulbs to cover area.

Also one must considor the size of plant grown when fully matured indicas are shorter in nature than when compared to sativa plants !

I still may go HPS/MH as I haven't built the lighting setup yet, but I have everything else already so I don't want to have to buy bigger fans at this point if I need a 600W HPS setup. Would I need a separate fan for a cooled light hood, or just route my current one through the hood with duct and use it as the primary exhaust fan as well?

Thanks again!

Some growers use a seperate exhaust fan for air cooled hoods...

But you can use current fan route through hood & carbon filter, lots of people use this method...





I've used CFLs 6400k (blue spectrum) for germination and veg up to 8 weeks before & still do

 

[TX-Skydiver]

Yep, Texas it is and my main concern was the heat issue with the HID lights. Mainly just not having to deal with it for my first couple of grows. Just thinking I'd easy my way into it without complicating it too much for myself as I learn. After all the advice so far from you and the others though, I think I may have been overestimating the complexity of an HPS/MH setup. I actually though about putting in a fake wall essentially cutting the room size by about 40% until I'm ready to grow 12 plants and use the entire space. This should help with the "squarish" light pattern i think.

On the odor issue, I have a six plant hydro set up so I'm guessing they may be a little stankier

 

[Fuzzy Duck]

If your lights on temp with fans running remain stable between 24c and 29c ya be pretty much fine

Over 30c or at least 32c for a prolonged period time may stunt the growth a bit, thats like a few days or more... Co2 is often used in high temp enviroments also... so thats another choice at hand & even DIY options are aviable !


Some of us will prefer to have the lights on period during the real life night time as the ambient temps are lower, ambient temps effect inside of grow room also once you factor in heat generated by bulb & how effective the exhaust fan is...

As ya running AC i can not comment as i don't live in a part of the world which use's AC... all i got to think of is high summer temps & running the central heating during winter which both may effect the growing enviroment temp wise on average i'm about 26/27c lights on lights off 19/20c apart from the odd high temp peaks in summer


Reflector design either being square or rectangle in design may give you an idea of light foot print as in size/shape etc...

The greater the height the bigger the light foot print... but the square law of light really does start to play a factor in this & in general a HPS/MH will loss 1/4 of its power i think its (lux) per 1',12" or 30cm of hanging height.

So if i hang a 400w at at 12" above plants & in theory i'm really getting 300w to the plants (example only) i've seen charts but can not find one at the moment for greater benifit.

2. CFLS really do suck when it comes to the square law of light effect... they start to loss light value & penertration every inch above the plant & not good for bush type plant grows.


HPS/MH its not really that complex its just theirs a few basics to be concern with e.g effective light foot print per bulb wattage & safe hanging height as not to burn the ol girls...

Core light foot print on average & aprox safe hanging height with standard reflector

250w 2' by 2' area - 6" to 10" aprox distance.

400w 3' by 3' area - 12" to 18" aprox distance.

600w 4'by 4' area - 16" to 24" aprox distance.

1000w 5' by 5' area - 18" to 30" aprox distance.

If using an air cooled hood you get away with some 6" to 8" close than the stated lowest hanging distance aprox, means more light energy to the plants & in theory a better yield !

On average a 600w HPS will out perform a 1000w HPS, 600w is pretty optimal for its size btw



I haven't really gone into PAR & LUX etc thats abit beyond me... but Hosebomber knows a lot about lighting and you may wish to view this - The Basics Of Plant Lighting for any other details you may wish to know

 

[Graytail]

 

[TX-Skydiver]

Fuzzy Duck & Graytail,

Thanks a ton for those last two posts! I appreciate you guys and all the others for taking the time to write such elaborate posts. It's all becoming a lot clearer now

As far as the lighting schedule, what I've read most is 24/0 until about 16" tall or so and then 18/6 (not sure for how long?) followed by 12/12 for flowering. I have also seen a lot of posts suggesting that you wait 24 hours between the off/on during flowering?? i.e. if you turn them off at 6 pm then don't turn them back on until 6pm the next day and then run your 18/6 or 12/12 cycle again. Am I understanding that correctly, or is that even how you should do it?

 

[Graytail]

That's another one of those debatable subjects, like ph, heheh - everyone has an opinion and everyone does it the way they want to.

I've always vegged under 24/0, but I'm starting to think that they probably benefit from a dark period, so I'll guess I'll put a timer on it one of these days. I'll probably go 20/4.

Another variation is green lantern routine - GLS - which is basically 12/12 with an hour of light during the night. This stops them from flowering. People claim minimal difference in growth rate, and I dunno why they'd lie about it. The idea is you save on electricity, and GLS will kinda "prep" them for flowering and they'll react faster.

You'll get a lot of opinions.

 

[Graytail]

Here's another useful chart for you: