Do I really need a reflector?

shaqfu

New Member
Hi All,
Just another quick question, planning a small grow (2 plants) in a 1m x .5m cabinet with intake/exhaust fan and 1CFL , in my noobie excited state I went
and bought some sheet hammered alu to make a reflector with, but looking around at some people's set-ups, most dont use reflectors??

Thanks,
Shaq.
 
Oh right Ok cheers, any particular reason not to use a reflector with Flouros,
even if im trying to grow two plants with one lamp?!
 
Yes I was going to make one like this


As I have the sheet metal and tools to do it :D
Cabinet will be all white inside .

Cheers.
 
Yep, I got two of those EZ roller thingy's aswell :D

I dont have ballast with these, seller's website said It didnt need it for 124W bulb ?! :)
 
Ok cool, I'll see what works best on my set-up. Thanks everyone really helpfull this place :D

Just another quick question if I may on here instead of starting a new thread?
Do you guys run both fans on all the time, or is there a quiet period?
 
You mean, ventilation or plant fans?

I use fans right on my plants, so they wiggle a littl'.
I've played with that,
fans 24/0 and set to what ever the lights on cycle is,
ones with 24/0 seemed to be shorter and stouter than the others.
Which is what I expected to see.
*But* the difference was so small you won't know it
unless you were testing it/looking for it :cheesygrinsmiley:
 
Using a reflector is even more important with cfls due to the relatively low output. Any light that is traveling upwards is wasted and it is not intense enough to be reflected back from the ceiling and still be usefull. If you have 10000 lumens output @ 1 foot, at 2ft you only have 2500, @ 3 ft = 625, 4 ft = 156. That is why you keep cfls as close as possible and MUST use a reflector and even then your lower buds will be struggling for light. Boss i know you didnt use a reflector on your grow and got plenty bud, but you had loads of bulbs in there and would have upped your light by about 40% using reflectors, finished sooner and yeilded more. Or you could have taken some bulbs out and kept the heat and electric bill down, .

A 23w cfl has about 1300 lumens, if light has to travel 2ft to the ceiling you get the initial 1300 lumen to the canopy from the bulb and the reflected light has to travel 4ft back to the top of the canopy so the intensity is only 20.3 lumens (assuming 100% reflection) total = 1320 lumen. With a reflector 6 inch away the light travels 1ft back to the canopy and contains 325 lumen. Total = 1625 lumen. Add to this the fact that most reflectors are closer than 6 inch to the light and have a higher percentage of reflection than most ceilings and you can start to see how important they are. The more light you use without reflectors, the more energy you are wasting.

All bulbs (hid + cfl) also emit more light from the sides as they have the greatest surface area releasing light. If a bulb is vertical it gives most of its energy to the walls to be reflected back (again losing intensity) A horizontal bulb with a reflector is by far the most efficient. And a matt white painted reflector beats ANY OTHER relector, polished, hammered, steel or aluminium. so get that reflector made and a tin of matt titanium white paint and you will be doing the best you can with the light you have.:allgood:
 
And btw 125w envirolights are self ballasted same as a household cfl. and are good lights but the 200w can be bought with seperate ballast for not much more money and then you get more power and only have to buy the bulb when you need to replace. (which is cheaper than a 125w self ballasted) If you havent used it yet i would consider returning it for a 200w. It wont cost much more and you get more lumens and can keep the hot ballast out the grow space.

I think the reason most people dont use a reflector for the cfls is because normal fittings will hold the light adequately and cheaply so will work without one. Hid growers are working with higher temps, wattage and tend to be more serious about there grow so know the importance of a reflector. Plus hid have a e40 screw fitting and need to be well supported and safe due to the heat. A reflector does this perfectly whereas a mgyver style bodge up is just too dangerous for hid temps and current. Plus the bulbs cost more, like your 125w, so people take better care of them. Household cfls are so cheap people just add more rather than making/buying reflectors to make them more efficient
 
You mean, ventilation or plant fans?

I use fans right on my plants, so they wiggle a littl'.
I've played with that,
fans 24/0 and set to what ever the lights on cycle is,
ones with 24/0 seemed to be shorter and stouter than the others.
Which is what I expected to see.
*But* the difference was so small you won't know it
unless you were testing it/looking for it :cheesygrinsmiley:

On a scale from 1 to 10 how effective was leaving the fans on 24/0.
 
I think the reason most people dont use a reflector for the cfls is because normal fittings will hold the light adequately and cheaply so will work without one. Hid growers are working with higher temps, wattage and tend to be more serious about there grow so know the importance of a reflector. Plus hid have a e40 screw fitting and need to be well supported and safe due to the heat. A reflector does this perfectly whereas a mgyver style bodge up is just too dangerous for hid temps and current. Plus the bulbs cost more, like your 125w, so people take better care of them. Household cfls are so cheap people just add more rather than making/buying reflectors to make them more efficient

Yep. Agreed. I had reflectors up, but they just didnt fit right, got in the way of keeping the lights close, so I just added more light.
 
Using a reflector is even more important with cfls due to the relatively low output. Any light that is traveling upwards is wasted and it is not intense enough to be reflected back from the ceiling and still be usefull. If you have 10000 lumens output @ 1 foot, at 2ft you only have 2500, @ 3 ft = 625, 4 ft = 156. That is why you keep cfls as close as possible and MUST use a reflector and even then your lower buds will be struggling for light. Boss i know you didnt use a reflector on your grow and got plenty bud, but you had loads of bulbs in there and would have upped your light by about 40% using reflectors, finished sooner and yeilded more. Or you could have taken some bulbs out and kept the heat and electric bill down, .

A 23w cfl has about 1300 lumens, if light has to travel 2ft to the ceiling you get the initial 1300 lumen to the canopy from the bulb and the reflected light has to travel 4ft back to the top of the canopy so the intensity is only 20.3 lumens (assuming 100% reflection) total = 1320 lumen. With a reflector 6 inch away the light travels 1ft back to the canopy and contains 325 lumen. Total = 1625 lumen. Add to this the fact that most reflectors are closer than 6 inch to the light and have a higher percentage of reflection than most ceilings and you can start to see how important they are. The more light you use without reflectors, the more energy you are wasting.

All bulbs (hid + cfl) also emit more light from the sides as they have the greatest surface area releasing light. If a bulb is vertical it gives most of its energy to the walls to be reflected back (again losing intensity) A horizontal bulb with a reflector is by far the most efficient. And a matt white painted reflector beats ANY OTHER relector, polished, hammered, steel or aluminium. so get that reflector made and a tin of matt titanium white paint and you will be doing the best you can with the light you have.:allgood:


Thanks George, thats a very helpfull and informative post, will get the reflector made Asap, this afternoon infact. Will go/grow with 125w for now i think and maybe I'll try 200w for the next grow.

Quality signature btw :D:allgood:

Cheers everyone.
 
I took into account the sag they have on them on the first versions I have seen, and bent up the lamp holder bracket to compensate.

Im really pleased with it, gets quite warm though!
 
Hi shaqfu. The 125w will be just fine and will be more than good enough, just make sure to keep it close and if your plant gets too tall or bushy to let light through to the lower branches just put a few normal cfls or some tubes around the side. Another thing i would think about is topping the plant early, and dont forget that it will keep growing when you put it in flower (even more if you dont top it) some times 2 - 3x the height it was when you switched the light to 12/12

I should have said b4 to be wary about what paint to use. Some paints (mainly gloss paint for wood) could be a bit unpredictable when they get hot. They could be likely to yellow or melt or even catch fire (unlikely but possible with hid bulbs) The envirolight will not get anywhere near that kind of temperature so dont worry if you`ve already painted it with a gloss paint. I would recommend radiator enamel. It will dry to a gloss finish but when it is completely dry give it a light rub with some fine grade wet and dry sandpaper to take the shine off it. Or it might be better to use some wire wool as your hood is hammer finish, because it will be easier to get into the dimples. Just be sure to put plenty of paint on and make sure the paint is completely dry (use the reflector for a few days so it gets warm and cures the paint) and dont press to hard with the sandpaper of wire wool so you dont break through to the metal. You can also use the high temperature engine paint that you can get from the auto spares shop but i think that radiator paint is closer to titanium white which is the most reflective white colour. Or try a model/craft shop for titainium white enamel.

Glad you like the signature, those words are very true and should be remembered by us all to keep us on our toes. Some people think a little paranoia is a bad thing but it has saved many peoples bacon over the years. I can`t take credit for them though, it`s a line from a song by the late, great kurt cobain. Or maybe you already knew that?
 
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