DIY setup, 3.5 ft footprint, HPS questions, help please!

[Diemand Edge]

So I've got about 3 plants that have been vegging for close to four weeks. In two weeks or so, depending on how the girls are looking, will be switching over to 12/12 lighting to induce flowering (they are running 18/6 now). Currently they are under 8 CFLs, 23-26 Watt, putting out about 13,000 lumens. The lights are mostly 6500k spectrum (6 out of 8) and two are 2700k.

When I go for the switch over to flowering, I'm seriously considering an HPS, approximately 150W. I'm wondering what is the best sized HPS, how much cooling is really necessary (cool tube?), and since I've got a fairly small cab, is it too much? Dimensions of the setup are approximately 34 L x 16 D x 34 H.



I want to succeed as much as possible, so any help or advice is greatly appreciated!!!

 

[BWC BayArea]

I'd suggest goint with a 400W digital (if possible) ballast and an inline fan between 120-150 cfm to cool lamp and/or exhaust for 3 plants. Are ur dimensions in inches or feet? I thought inches at first but u cant veg for 4 weeks and then go into flower with a 16" height restriction. If u have that much space. Go with a 400W or 600W and grow big plants. U may even wanna consider a 1kW. U'll need larger fans to cool the larger lamps of course. Post some pics if u can. U got a reflector on the cool tube or is this a verticle grow?

 

[Reefa Cheefa]

My first grow I used a 150w HPS. It was ok but I know I could have had a lot more bud. A 150w doesn't give off nearly as much heat as a 400 or 600. A few fans and your all set.

 

[ledtester]

So I've got about 3 plants that have been vegging for close to four weeks. In two weeks or so, depending on how the girls are looking, will be switching over to 12/12 lighting to induce flowering (they are running 18/6 now). Currently they are under 8 CFLs, 23-26 Watt, putting out about 13,000 lumens. The lights are mostly 6500k spectrum (6 out of 8) and two are 2700k.

When I go for the switch over to flowering, I'm seriously considering an HPS, approximately 150W. I'm wondering what is the best sized HPubt, how much cooling is really necessary (cool tube?), and since I've got a fairly small cab, is it too much? Dimensions of the setup are approximately 34 L x 16 D x 34 H.



I want to succeed as much as possible, so any help or advice is greatly appreciated!!!

Since you're growing in a small cab 150 might be the way to go...to be honest I doubt if you will be able to keep it cool enough with anything bigger...you only have 34'' height too so the plants can only get so close to the light

 

[drdanks]

the 400w would be good with the inline fan, but honestly your it doesnt sound as tho your growing for quanity, this is just for personal, then 150 would be ok. make sure to keep tabs on the heat at the top of the plant, you can get them close to the tops as possible, test this by putting your hand under the light, if your hand is comfortable then so will your plants, if its too hot for your hand then its too much for your plants. either way bud youll enjoy this test. After this time youll have so much more knowledge for next. enjoy! and good luck!

Stay up there

 

[TorturedSoul]

That's 3.7777777(etc.) square feet. Under optimum conditions, a 150-watt HPS throws 16,000 lumens which would give you ~4235 lumens per square foot. So you would be likely to get some bud. But that's a lower light level than many use. A 250-watt HPS might produce 24000 lumens which would be much better at ~6353 lumens per square foot. Bud would be denser and you'd have more of it - IF you were able to remove the heat. The 250-watt would also have somewhat better penetration.

Are you set up so that when you get the light it will be on top of your cabinet shining down into it or does that 34" include the plants, their containers, and any lighting? If everything including your light has to fit in there then you'd probably either be running an open-fixture setup with mylar or other suitably-reflective surface on the ceiling and good overall cabinet venting or a cool-tube setup - either one of the ones with a reflector built onto it or a homemade one - with separate intake/outflow for the tube and for the cabinet. I wouldn't run a cool-tube and pull air to cool it from your cabinet (although some do) as you'd lose some of the cooling that you'd definitely want in such a small space.

A 400-watt in that space would simply be too much light (and likely heat) for your setup.

EDIT: You could always go with a 150-watt HPS and add a few CFLs to supplement but then you'd have five sources of heat to deal with instead of one.

 

[ChicagoJoe]

My first cab had a 150 hps and some supplemental cfls.
The cab was 36"x18"x 72 .
The 150 provides really good light about 18" square and about 10 inches deep.
So if you are going to scrog, that would be perfect.

yours seems too short for a 400.

 

[Jasonlee247]

I'd suggest goint with a 400W digital (if possible) ballast and an inline fan between 120-150 cfm to cool lamp and/or exhaust for 3 plants. Are ur dimensions in inches or feet? I thought inches at first but u cant veg for 4 weeks and then go into flower with a 16" height restriction. If u have that much space. Go with a 400W or 600W and grow big plants. U may even wanna consider a 1kW. U'll need larger fans to cool the larger lamps of course. Post some pics if u can. U got a reflector on the cool tube or is this a verticle grow?

manufacturers recommend 1000w per 10ft. Thats what? 100watt per sq.ft.

I have a 250w HPS light with a 270w Son t Agro bulb in a 2x2' space with 5'vert max. totally sealed other than a 4' intake and exhaust. I use a 4" inline duct fan w/ 150cfm (cubic feet per minute) and get great results. a 400 would cook my plants and be exessive for the space.
Below is 1 pinched Cinderella99 4weeks into bloom under nothing but the 250hps:

With a little planning you could incorporate the CFL's with a low wattage HPS overhead, or just go for it with the CFL's, but your yield will be lower.

 

[Jasonlee247]

oh, and my 250 is Old SkOOl with an internal ballast. extra heat.

 

[TorturedSoul]

manufacturers recommend 1000w per 10ft. Thats what? 100watt per sq.ft.

That's pretty high, actually. 30-50 watts per square foot (of HID lighting) is adequate for the vegetative stage and 50-70 watts per square foot is adequate for flowering.

Many moons ago I ran 102 watts per square foot and had I not been supplementing the CO2, I expect that much of that light would have been wasted.

Your setup looks pretty good and your plants should do well.

oh, and my 250 is Old SkOOl with an internal ballast. extra heat.

That fixture's ballast can easily be removed and "remoted" - all you need is a decent metal enclosure to use as a ballast box and a few other things. I believe there's a thread or two on this site covering how to do it. If you are adequately-covered as far as heat in your GR that is great, but otherwise, modifying an all-in-one fixture is pretty simple.

 

[Jasonlee247]

That's pretty high, actually. 30-50 watts per square foot (of HID lighting) is adequate for the vegetative stage and 50-70 watts per square foot is adequate for flowering.

Many moons ago I ran 102 watts per square foot and had I not been supplementing the CO2, I expect that much of that light would have been wasted.

Your setup looks pretty good and your plants should do well.



That fixture's ballast can easily be removed and "remoted" - all you need is a decent metal enclosure to use as a ballast box and a few other things. I believe there's a thread or two on this site covering how to do it. If you are adequately-covered as far as heat in your GR that is great, but otherwise, modifying an all-in-one fixture is pretty simple.

Adequate, YES, optimal, not nearly. not even a 1000w HID would come close to the sun, so the more the better -reasonably. I too started with a 100mh & HPS, so i know that they will work and give decent yields. I've also ran 1000's farther than recommended and had good results, but if your looking for those monster buds more is better. (you know what I mean)

I would remove my ballast, but I'm lazy, and my temps ever hit above 87, so I'm just like 'whatever' lol I run days on in winter and nights on in summer, so it actually helps the heating bill. lol I run fermentation Co2 occasionally. not as much as I should, but ah. I do good. I just hope that I can give Diemond some Ideas.

 

[MountainHigh]

I am not sure for that small of space, honestly I think the likelihood for a great outcome will be found with CFL's, something like 3-5 65w (300w equivalent) in a setup something like the Skooterclown's have with Mylar walls. Construct your own fixture that is vented (4 inch would be fine or maybe even a couple large computer fans on it drawing air through it) and fills the top so the heat and air from cabinet has to be drawn out of it's exhaust vent.

Here is a picture of it from this thread Growing with CFL's in very limited space...

And this is what they get out of those cabinets...are buds like these. See this thread.

CFL's give you more headroom...150 watt HPS needs 8 inch from both the plant and the ceiling generally (unless metal or covered with that insulation stuff)...400 would need 12 each direction...and that doesn't add in the bulb width and fixture height and hanging attachments...there goes most of your height adjustment.

CFL's are generally safe at 3 inches on either side.

Something to think about. You could make the above fixture with more sockets and use smaller CFL's.

If you do set up an HPS, I would use a cooltube and a 250watt. Horizontally mount the tube near the top and insulate it. The cool tube would go all the way through the box in my setup...it would always be cooled with air from outside the box that way. It would be permanently mounted and I would make height adjustment for my plant...shelves probably, but like mesh, not solid. I would have 4 pancake fans in the top...larger quieter ones drawing even more air across the cool tube and out of the box so there is no heat buildup from irradiated heat off the reflector of the cooltube. The box would have vents cut in the very bottom all the way around the box.

That is how I would lay it out anyway....

 

[BWC BayArea]

In a space that small I have zero experience. Listen to these guys here that have journaled or done this type of grow before. That is a tight space to grow in. But if its just head stash sounds like it may do the job. Good Luck.