1 meter ceiling - Diagonally positionned HID light to have 30-40 cm from plants

Hello, my first grow and my first post in here. Willing to grow 2 feminized Kalasjnikov 2012 autoflowering seeds from magic seeds.
After tons of research and reading I finally ordered everything I need from ph meter, ph plus minus, dehumidifier, switch timer, etc… and while waiting for the shipment I bought a light fixture that can work a 400w MH/HPS with built in magnetic ballast, bought 1 mh and 1 hps bulbs, t5 fluo fxture and some CFLs as a backup lighting for my future plants.

The attic where I want to grow only have 1 meter height in total which I know isn’t enough for MH/HPS lighting. What I’m thinking about is hanging 2 fluo T5s directly above the plant, backed up with 4 40w CFLs (or more if needed). And for the HID i have to find a way to make the proper spacing between it and the plant.

Now my questions is can I hang the HID light diagonally on the upper corner of my attic ? (below a draft to be more clear) i know it is better than no MH/HPS and it will certainly give a great light that the plant needs. Is there any problem that I might have with this setup ? will the plant grow uneven or badly because the MH light hits one side more than the other ?

I’m very motivated and exited for this grow, I really put some hard efforts on this and as i'm planning everything before i start this is the main problem that needs your smart ideas. Maybe I’ll start a journal when I start

I think it depends on how much effort and homework you are happy to put in.

A 400w hid for two plants is plenty of light, so if you can fit it all in and make it work, then you probably should.

If you can afford a cool tube, you could reduce worries about height/burning a lot, a cheaper option than this would be to get a heat shield to place under the bulb. I used a heat shield under a 400hps several years ago (only stopped due to outside reasons) and could get the light maybe 15 cms from the plant tops iirc.

With either of these ideas you would want all of the flowering tops at about the same height, so you would need to train the plants in some way, such as by tying them down or SCROGing - this is easily done, effective and only needs a bit of reading up if you aint familiar with the process.

To save height, maybe go with a shallow (short) pot that has loads of width so roots still get plenty of space to grow/feed.

bear in mind you would need to train the plants to be as short as possible and check regularly for burn, testing heat at plant height by holding your hand under the bulb - if it's too hot for your hand then it's too hot for your plants too.

Hope this helps

Or grow vertical on a 3' wall with lots of training and hang the light horizontally. No matter what method your gonna need to do some massive training. The autos may stay short as well but I'm not an indoor auto grower. Heat may be an issue as well if it's a typical attic. Good luck and post results as you get along

pitchforksandtorches said:

I think it depends on how much effort and homework you are happy to put in.

A 400w hid for two plants is plenty of light, so if you can fit it all in and make it work, then you probably should.

If you can afford a cool tube, you could reduce worries about height/burning a lot, a cheaper option than this would be to get a heat shield to place under the bulb. I used a heat shield under a 400hps several years ago (only stopped due to outside reasons) and could get the light maybe 15 cms from the plant tops iirc.

With either of these ideas you would want all of the flowering tops at about the same height, so you would need to train the plants in some way, such as by tying them down or SCROGing - this is easily done, effective and only needs a bit of reading up if you aint familiar with the process.

To save height, maybe go with a shallow (short) pot that has loads of width so roots still get plenty of space to grow/feed.

bear in mind you would need to train the plants to be as short as possible and check regularly for burn, testing heat at plant height by holding your hand under the bulb - if it's too hot for your hand then it's too hot for your plants too.

Hope this helps

Click to expand...

this is what i'm going to be using, it has no cool tubes but it has a glass that should stop some heat. also, i prepared like 7 or 8 PC fans and a big oscillating fan than will help with the heat issues. will do some heat testing after everything is installed, maybe if i needed to i will cut the light fixture on the side to fit a pc fan to help blow hot air away.
I will go and get a short and wide pot, and prepare a net for scroging. i will be doing lots of LST!
i think i will go with the plan and setup everything as the sketch i did as soon as the shipments are here. will post photos also

Thats gonna put out an absolute ton of heat in that space, plus however hot your attic is due to what ever your local climate is, combined with whatever insulation your attic has. The HID will draw the plant's growth towards it too, as it's much stronger than your cfls etc.

I doubt that the glass will stop any significant amount of heat. Definitely do your heat testing to work out where the danger zone is, by using your hand under the lamp for about 20-30 seconds, and then rigorously train the plants to that height and check on them regularly, adjusting positioning in the SCROG (or w/e) as you go.

I'm guessing you have an extractor? You don't mention one but you will need it with that light in a small space.

Your plan is do-able, but just do plenty of testing and keep growth as low in your box as possible or you will fry your babies.

Like Budley said above, growing vertical is an option to explore too.

The glass won't do anything really, I would actually remove it , and yes you need to pull fresh air in and exhaust air out, not only for temp control but to keep the CO2 levels at or near normal. Put your intake exhaust right at the light and that will help.

Budley Doright said:

The glass won't do anything really, I would actually remove it , and yes you need to pull fresh air in and exhaust air out, not only for temp control but to keep the CO2 levels at or near normal. Put your intake exhaust right at the light and that will help.

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i already planned the air circulation in the room, air will be pulled from inside of the house and out of the attic through an existing pipe on which i will connect a PC fan to push the air from inside out.
do u recommend removing the glass even if i'm considering cutting a side of the light fixture to connect a cooling fan ? or that would work better with the glass on ?

That's going to need to be one figging enormous pc fan.

Like the worlds biggest one ever.

Air circulation is great, but you need proper extraction too or your grow will fail, especially in such a small space where you will be doomed darn quick.

At the very least, get a cheap bathroom extractor, and have some passive air intakes to your space. Such as shaded grills that wont let light in.

Or better still get a small rvk fan or similar. You will still need passive intakes with these too at least. Actually maybe use a pc fan to push some air into the room seeing as you have a few

Look into it, you really need it, that light will bake the s*** out of that tiny space and your plants will eat through what little air is in that space, you need to remove the heat and give the plants fresh stuff to breathe.

btw, have you already purchased your light? You may have better options for a similar price.

What's your summer and winter temps?

WeedBudz said:

i already planned the air circulation in the room, air will be pulled from inside of the house and out of the attic through an existing pipe on which i will connect a PC fan to push the air from inside out.
do u recommend removing the glass even if i'm considering cutting a side of the light fixture to connect a cooling fan ? or that would work better with the glass on ?

Click to expand...

Pulling air from the house and not replenishing it is not a great ideal, but if your using a PC fan you'll be ok in that respect cause you won't be pulling much .

pitchforksandtorches said:

btw, have you already purchased your light? You may have better options for a similar price.

Click to expand...

Yes i have already purchased the light with 1 mh and 1 hps bulb. i will try to work with what i have, planning to cut through it and direct an additional room fan directly beneath it.
i will get a bathroom fan (maybe 2) to improve pushing air out of the room, and i will add another one on the opposite wall to push air from inside of the house to the attic (which will be approx 25 degrees celcius). i think this will be enough for a start.

Budley Doright said:

What's your summer and winter temps?

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For the temps August is the hottest month with an average temperature of 28°C (82°F) and the coldest is February at 13°C (55°F). the highest humidity month is January.
So if i started the grow soon, and as the temps are getting lower and lower each week, the heat of the light might actually be helping to increase the temp of the room and the automatic heater might have less work to do.
for the summer i will have to figure out something else but till then i have plenty of time for 2 auto flowering trials

Just noticed i never mentioned the dimensions of the attic it is 2.35 x 1.60 meters with 1 meter height.
it is fully painted with white anti humidity paint.

just did a little test and the glass definitely reduces heat under the light! guess i'll keep it and add these 2 fans each on a side after cutting holes, in addition to a big room fan aimed directly on the lighting glass. what do u think guys ?

Where is the intake and exhaust? Not gonna work without them

SPLFreak808 said:

Where is the intake and exhaust? Not gonna work without them

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This model doest have an intake and an exhaust, i will cut it myself and put 2 fans 1 as an intake and the other as a exhaust

WeedBudz said:

This model doest have an intake and an exhaust, i will cut it myself and put 2 fans 1 as an intake and the other as a exhaust

Click to expand...

I did the same with my winged reflectors but just cut intakes into the tops and it worked great, at 55 your probably going to want to pull that in to the room for sure and at summer temps your gonna have an easy bake oven , even in winter if the roof is exposed she may get really hot ...... fuck wanna trade places, minus 20 here and high 80's with 100% humidity in summer .

Budley Doright said:

I did the same with my winged reflectors but just cut intakes into the tops and it worked great, at 55 your probably going to want to pull that in to the room for sure and at summer temps your gonna have an easy bake oven , even in winter if the roof is exposed she may get really hot ...... fuck wanna trade places, minus 20 here and high 80's with 100% humidity in summer .

Click to expand...

Guess it doesn't really matter when u have an insulated grow room with the right equipment

WeedBudz said:

Guess it doesn't really matter when u have an insulated grow room with the right equipment

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I just scavenged all my stuff but I work in hvac so yup lots to scavenge lol. And it matters when In heading to the shed at 5am in my bathrobe and it's minus 35, it matters a lot lol.