My first attempt currently consists of three small plants, growing in three separate pots of about 30cm height and 15cm radius, growing inside a bedside table about 1m tall. The pots are filled with some pre-fertilized soil I bought from a local garden store. The plants have so far been grown each under their own 13W CFL, and today they were finally set up under a pair of 85W CFL's placed inside a tinfoil lined bell. These are placed horizontally, so as to maximize the surface area facing the plants. There are two small holes in the side of the bell where a couple of fan coolers are drawing air out - though I'm thinking of reversing airflow to shake up the plants a bit and help them develop stronger stems and branches. The plants themselves actually seem to be doing pretty well, in spite of the fact that they were growing under such poor light. One thing I did notice is that their color was a bit lighter than expected. Also, I'm worried that the lights may be too far away from the plants (around 50cm). I'm expecting for the color to improve after they've been under the new lights for a while, but I'm wondering if I should lower the bulbs a bit. What distance should there be between the bulbs and the plants? I'll try to post pics soon.
I've read lots of people say on this forum that you should place them as close as you can with your hand just above the canopy and if you feel more than a slight warmth than it's too close-- nothing at all and it's too far. Though I have no experience with this type of lighting myself. Really no experience in general, but this is what I've heard.
With cfl's you want your light as close as possible to the plant to prevent stretching, but not so close as to burn the plant. If I'm doing my math right you're looking for between 5-10cm or 2-4in. Cfl light degrades over distance quickly. Also be careful with the foil,the little creases in it can create hotspots, focusing the light almost like a magnifing glass and the sun, burning the plants. Lastly, you have to be extremely careful with pre-fertilized soils as every time you water you are releasing the time released nutes into the soil. It's very easy to get nute burn with these soils. This is especially dangerous for seedlings. I hope this helps. Good luck
this really isnt an issue for CFL's. They arent intense enough to create hot spots. FYI, flat white paint is more reflective than foil.
Yeah, I've heard about white paint being better, but it was unavailable at the time of building. I'm thinking of removing the tinfoil and lining the inside of the bell with white cardboard or white paper. Would it work aswell? Our current light set up is rather unmoving, so I told my buddy to prop the pots up using books in order to get them at least 2.5in away from the bulbs. Hopefully that stoner remembered. I guess what we'll do is start removing books when the plant starts growing. Edit: Ok, here's my shitty cellphone pic (my camera got stolen last year, sorry ) The plants will be propped up soon, so there's only about 2in between the plants and the light. I'll try to get a pic then. Sorry, no close ups, I got paranoid and deleted them I'll get some of those, too.
Good idea with the books. I would wager a guess that the whole white paper would work, or you could just go buy a mylar "emergency blanket" at wal mart in the camping section for 3 bucks.
Allright, the plants got propped up and are now at a much more decent distance from the bulbs. I also noticed that due to the disposition of the bulbs the center plant was getting a far smaller ammount of light, so I added a couple of 13W CFL's on top of it to help out. Here's how it looks now: (Again, sorry for the shitty pics.) And some close ups of the plants: (This little one is my favourite) Any imput regarding how to improve the setup or possible yield would be appreciated.
I've noticed a bit of discoloration/burning on the tip of a couple of leaflets of the smaller plant - Could this have been caused by the proximity to the bulbs? I will be replacing those two 13W bulbs eventually for some larger ones (Probabbly 26W, larger if I can find/afford them) and I've been wondering about the light temp. I've heard for flowering the ideal temp is 2700K. These are all currently 6000K. Since my main source of light will still be those larger 85W 6000K bulbs, will there be a noticeable difference in yield if the smaller bulbs are 2700K? I'm asking because finding them might be problematic, but if the difference is worth it I'll try to get them.
I tried flowering some plants under a 200W floro at 6500k. They did flower but there was noticeable difference in yield and bud development. The veg lights seem to grow airy buds compared to the denseness of nugs grown under warm colored light. My advice is to get some more bulbs for flower.