Using Envirolites ONLY 3cm-4cm above plants

I have read (the manufacturers advertisment http://cgi.ebay.ie/GENUINE-ENVIROLITE-125W-GROW-LAMP-BRAND-NEW-STOCK_W0QQitemZ7762875349QQcategoryZ43555QQtcZphotoQQcmdZViewItem)
that these types of lights work best when used only 3cm to 4cm above the plants.
Is this possible. I have placed a 200 watt Envirolites only a few inches above the plants and have notices the stems on the top braches have turned a bright purpleish colour. However, the plants do seem very healthy. Are these purple stems/branches from the light being too close? Any idea, comments, suggestions are welcome!

 

No some strains are naturally purple. Put your hands above the plants for a few seconds if its not to hot for your hand the plants will be OK. I generally have a fan blowing across the tops of the plants. This cools things so the plants can be closer to the lights. This increased air flow helps growth rate and reduces chances of pests and mould. An oscillating fan blowing on your plants is an essential piece of kit.
Generally the closer the plants are to the lights without burning the better. When plants are to close to the lights they firstly bleach yellow then turn brown as they burn. Like I say if you test with your hand for a few seconds there should be no problems.

 

Thanks BuffoonMan, Yes, I am using an oscilating fan. I will lower the light back down to give them more light.

 

I would with envirolights and flourescants its even more important to have the lights as close as possible. Will be interested to see how your plants do as I have been thinking of using envirilights for an extra veg room.

 

The importance of putting florescents so close is to do with the lumen capacity as far as I know.

A standard 40W florescent tube will produce about 3000 lumens, which is JUST enough for healthy plant growth up to 12 inches away. If your flo is 6 inches from the top of your plant, that is only 6 inches of productive lighting. In other words, only the top 6 inches of your plant will be getting sufficient lighting.

I haven't seen a 400W envirolite, and I can't find any actual lumen ratings for them, so I will just base it on a 70 lumen per watt, similar to a standard flo.

A 400W envirolite will produce about 28000 lumens at 12 inches. Which means the light will penetrate to about 36 to 48 inches and still provide adequate lumens. Since you can hang the light within 1 to 2 inches, that means you can penetrate the plant up to 34 to 46 inches with adequate lighting capacity.

A 400W full spectrum HPS will get about 55000 lumens at 12 inches away. Which means the light will penetrate to about 48 to 60 inches. Since the lamps burn so hot, you usually hang them about 12 inches away, or more. That means you are getting a penetration depth of 36 to 48 inches with adequate lighting.

Now also consider that even a full spectrum HPS has a much broader range of spectrum than a plant requires (something like 100na to 2000na, almost 80% wasted light), compared to the 100% usuable spectrum that a CFL has (300na to 700na) and it's not hard to realize that the Envirolite is more productive.

What I think is funny though, is that these envirolites are claiming to be so unique and so perfect for growing, but all they are is giant florescents. They dont' have any special spectrum at all. The lamps they claim are 'flower' lights are just warm whites. And the ones they claim to be 'veg' lights are simply cool whites.
Check your household flos and you will see that a warm white is a 2700k lamp and a cool white is a 6400k.

 

These enviro light people make some pretty wild claims about there output and useable light check the envirolights out under the hydroponic section at
http://www.theonlineelectricalwholesaler.com/catalog/index.php

 

Like you say though you can't beat HPS

 

Actually I wasn't referring to envirolite as the brand, but just the mogul CFL's.
All florescents have a very similar PAR.
I realize their claims to 100% usuable light is silly, but that is mainly because the 500na to 600na range is green/yellow light, which the plant reflects, it doesn't use it.
So it's actually only 70% usable light.

But when you compare that to the less than 20% usuable light that a HPS will emit, those wonky looking CFL's really shine.

 

What do you use Nickelbag? The advantage I can see with envirolites is that they are a lot smaller hence the light is more concentrated. You can fit four 200W bulbs in a reflector giving you 800W the lumens per given area are therefore a lot more powerful than striplights.

 

I use CFL's.

The direct advantage is spectrum.
A 200W Enviro will put out about 15000 lumens in the proper range of the color spectrum (visible light). A plant will use about 70% of the usable spectrum, because it reflects green. So 70% of 15000 lumens is 10500 lumens not only being shed on the plant but being USED by the plant.

A 250W full-spectrum HPS will output about 20000 lumens, but it's color spectrum is much larger. While it does supply the entire color spectrum the plant requires for growth (@ 350nm to 750nm). It also provides alot of light that is not in the usuable spectrum (<=100nm to >=1000nm).
So, 1000nm - 400nm = 600nm of unusable light spectrum that the HPS is emitting. That is a production efficieny of 40% (I made a mistake in my calculation in the other post of 20%).
40% of 20000 is 8000 lumens that is actually being used by the plant.

Notice also that I used figures from a 200W enviro and 250W HPS, so you will be saving watts too.

The indirect advantages are less heat and smaller. But these are insignificant compared to the benefits of usuable lighting.

 

To be honest, I have not noticed any dramatic difference in the quality of my grow since I switched to CFL's except that my plants don't stretch as much now.

The one thing that I do like about the CFL's over the HID's is the configurability.
With many lights it's easier to cover an area more evenly than it is with one high powered light.

I think the biggest factor in choosing CFL or HID would be your growing method.
I like SOG, so CFL's work great for maximizing the use of vertical space.

 

I've searched all day for any information that shows a spectral analysis of any type of HPS and I cannot find any. I did find one, but it was not very conclusive of anything. I suspect it's not something the manufacturers really want to reveal. I did find that a typical HPS lamp will produce about 125 PAR Watts.

An Envirolite will produce about about the same.

The difference is however, that the measurements are taken at the bulb, not at the target.

If a HID must be hung 1 foot from the plant, you can expect the light output to be 50% of maximum when it reaches the target.

In contrast, an envirolite can be hung within a couple of inches, thus nearly the full power of the emitted light is being utilized. Maybe 90%.

 

I have noticed since I swaped to an extented spectrum HPS (Growlux) bulb the plants don't stretch as much during veg. When I take cuttings soon will veg them with two 200W evirolites then flower with my HPS. Was thinking of buying one of these grow tents as a veg room have you ever tried one or read any reports on them?

 

Can't say I know what you mean by a grow tent.
I've never been one to buy into all the gizmos and such.
While most of the technologies the grow shops are selling do work, they are usually way overpriced, just because it's for growing.
I've found that I can take their ideas and make most of the stuff myself with alot less expense, often working even better than their cut-corner designs.

I suspect you are talking about some kind of mylar tent? An indoor greenhouse kinda thing? I'll have a look around and see what info I can find...

 

I see. I've made freestanding growrooms before.

Judging from what I've seen, those commercial ones look like they aren't too bad, though expensive, as I suspected.

Myself, I would prefer to make my own. Mainly because I'm cheap.
You could make one with copper tubing and mylar. Might cost you about $50 US instead of $200 or $300. 2 bars across the top of the box in the middle will support a lamp and reflector quite easily. 1 alone is a bit too flimsy I found.
One advantage of making yoru own would be that you could make it any shape/size you want.

It would depend on how much of a tinkerer you are, how much convenience you are willing to pay for and how discrete you need to be I guess. Although I don't think one of those grow tents would be too discrete anyways