Things to Know About Lighting

How many square/cubic feet? What kind of cooling?? If its warranted for the spece you should use both for flowering, and the MH for vegging..

born2killspam said:

How many square/cubic feet? What kind of cooling?? If its warranted for the spece you should use both for flowering, and the MH for vegging..

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The tent I'm using is 4ft x 4ft x 6.5ft, I'm using 100mm o/d carbon extraction and keeping the side flaps open for fresh air. Got a medium sized fan in the tent to circulate the air aswel.
The light I'm using is a single light fitting so won't be able to hav both lights I was going to switch the bulbs over wen it comes to flowering. Also got a humidifier in the tent to keep the humidity at 55%. Do u think it would be worth while to invest in a double light fitting system for my 400w mh and 400w hps bulbs? Oh n thanks for the reply much appreciated.

good question, i used the 400 hps for both, and got some fat tops, but, maybe i could have gotten more, i hear that more watts = bigger yield.

ya, u dont want ur girls getting 2 close to the light., i like the cfl's down below too

i got a thowy,!!!

I'm going to have fun. for 5 plants I'm going to be running during flowering 832w. 432 T5HO and 400 HPS. I think I'm gonna mount one T5 to the wall, hang the other from the sliding door frame, and run the HPS a bit above and between them, hanging from the shelf bar. 166.4w per plant. I think I'm going to get some great nuggage, especially using a DWC system. The closet is only about 2 feet deep, so the mounting of the T5HO like that should be optimal for the sides and bottom growth and the HPS should provide more than enough for the tops. My two seedlings, assuming they are female, will have to sit at the outside edges, because the clones are getting all of the attention!

Here's the current setup - only using 216w T5HO for the moment. Once they get 18-24 inches tall or so, I'm going to start flowering them and kicking on the other two lights.

Personally, I prefer buds that came off spots on the table that got maybe 20W/sqft, never cared much for the 2oz colas etc..
And if you're going to use that much light, you should add some CO2 to help them use whatever portion of it they can.. You're talking intensities likely exceeding the brighest sun that hits the planet for 12hrs straight.. I have a pdf on photosynthesis that explains why thats not really the best idea..
Have you considered running partial intensity for early/late day??

I practically live in the office where my closet is located. They get all the CO2 they need from my fiance and myself sitting no more than 10 feet away.

And no, I've never considered partial intensity for my normal lighting, I only use that rule with UVB bulbs during flowering. Everything else gets as much power as I can throw at it. Especially since I'm doing a mixed fluorescent/HID grow. The fluorescent works great, but it produces fairly dense plants and the canopy penetration isn't as good as an HID. The maximum best effective range for my T5 is about 18-24", but with a dense plant it's more like 12-15 inches.

I'm going for good lighting all around the plants, especially paying attention to the lower sections of the plant which tend to get poor lighting during flowering. The entire closet is say 16 square feet, so once all is set I'll put down about 50w/sqft. I will space the plants out to allow for as much growing room as possible without sacrificing light exposure. I am doing DWC, after all. It would be a shame to keep the plants small when this type of hydroponics is meant for yield.

melushell said:

you have any experience with that??? or you just 'know'??


LED Grow Lights.com Home Page
i am looking a lot lately into it, tough i still need to find relevant facts about the flowering stage
honestly i think it will be the future of artificial growing, NASA is already putting a lot of research into it

LED and aerogrow.....thats the future myfriends

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Okay, then come back and sell your LED's later in the future. Until NASA figures out how to make LED's work, I'll stick with my little teenie-weenie 150W HPS's.

Ok, I was thinking something closer to 8sqft.. Thats a wierd closet, 2ishx8ish.. On the partial lighting aspect, could you move the HID around in there?

born2killspam said:

Ok, I was thinking something closer to 8sqft.. Thats a wierd closet, 2ishx8ish.. On the partial lighting aspect, could you move the HID around in there?

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I could move the HID around a little bit but with the support hooks holding up the wooden bar below the shelf (which is what the HPS hangs from) it makes it a pain in the ass to move to the right. Here's a pic - you can see the support hooks behind the leftmost rope (helps support the old heavy-duty power strip) and behind the HPS ballast power cord. What's strange is there are no other support hooks - on the left side of the closet the bar is free and clear from the center support hook down.

Here's two pics to give you the idea of my closet. First pic is the right side, second pic is inside, sitting down (as far back as the near-vertical T5HO in pic #1 allows,) facing the left side. It's a narrow closet, and as it is both T5HO lamps have to be slightly raised towards the center of the closet so they can both hang equally, hence the idea of mounting/suspending the T5s to the wall/from the door stud with the HPS on top.

What kinda height you got total?? I know you're good at this, and will get it nailed, but if a noob posted those pics with those little guys creeping towards the ceiling I'd be worried..
On that note, what kind of results do you see with T5's as compared to HID (in flowering obviously)?? I've never used them, and most of the results with them are from noobs that were just too cheap to get HID, so I can't really hold those disappointments to the lights themselves..

For height I'm looking at a maximum of about four feet for the plants, from the top of the bucket to the safest bottom area below the HPS. For flowering, the T5HO will work quite nicely as long as a few caveats are observed. First caveat - two to three feet is the maximum usable range of the T5HO lamp, after that my light meter barely reads above 150, which is about useless for growing anything but algae and moss and lichens. Second caveat - T5HO lamps have only about fifteen inches of maximum canopy penetration. Below that, again my light meter reads around 150. Otherwise, for flowering they work out very well. The fact that T5HO bulbs output some UVB (whereas MH and HPS bulbs have to have a borosilicate UV filter) helps out with potency. It is true T5HO gets you just a wee bit less in density and weight unless you supplement or find a creative solution to maximize light exposure/usage, but that tiny UVB output does tend to make up for it in the power of the smoke.

For vegging T5HO certainly does the trick, though, as you can see from those clones. They've only been in those buckets for two weeks as of today, and when I first got them in there they only had three or four fan leaves. Even the seedlings, with their tops an easy seven or eight inches from the lights, are not stretching out at all. Growth between internodes remains very short, far less than a centimeter per node.

I like T5HO. I don't have to worry about special ballasts or conversion bulbs to obtain the color spread that I want, plus they make UVB T5HO bulbs so you can crank up THC production and have a balanced color spectrum all in one array. I do have to worry about plants burning if they get right on the bulb but otherwise it's not an issue. They really don't produce much heat, and they're pretty much silent. Figure out creative ways of maximizing light exposure and you can get explosive growth and incredible density, I'd wager, which is why I'm going to try that full canopy of light idea. If the closet were more square, I'd try disassembling my T5HO array and extending the wire, and putting them in a vertical configuration.

What does your meter read at the closest point you could safely let the plants reach?? (At centre tube and edges)..
I'm a GIANT fan of MH in the flower chamber.. Sure the plants directly under hps's were denser/beefier, but the ones getting primarily MH light produced much more enjoyable bud.. I don't know if it was due to increased UVB, UVA, or just bluer light, I just know that had no regrets about pawning off the bigass industrial sized hps colas and keeping my sweet MH nugs.. My favorite buds tended to grow where they were probably getting about 20W/sqft primarily MH light..

UVA doesn't work with THC, according to studies.

Let me whip out the light meter and I'll record an HD video for you so you can see the effective ranges and intensities for yourself at various spots. Give me a few minutes as this will take time to upload and whatnot.

err, more like half an hour. Stupid uploading speed is stuck about 25 k/s. 60 meg video to upload.

Ugh, it's going to take even longer - upload interrupted by someone using a microwave.

I was at 74%, too. vimeo really needs an upload resume feature.

Finally uploaded!!

http://vimeo.com/4753138

It may not show immediately - they have to convert it first, but the video is only a couple of minutes long so it shouldn't take much time at all, at most ten minutes.

Enjoy the show B2KS.

born2killspam said:

I have a pdf on photosynthesis that explains why thats not really the best idea..

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I would love to see it..

Could you copy and paste it over here?

Thanks!!!

Well, the way we measured the sun was at sea level. Where kush became landrace was quite a bit higher up, and thus the intensity is far greater up there, due to things like less atmospheric distortion, thinner air, plus the inverse law works every millimeter of the way from the sun to the surface.