collinsislee
Active Member
ive asked a few light questions already but im still learning and researching, would this setup be good for a closet set up? 6400k bulbs for veg, and 3000k for flowering High Tech Garden Supply
light question
- Thread starter collinsislee
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kindprincess
Well-Known Member
would work well for sog maybe, or small plants, but flouro's (including the almighty t5's) are generally reserved for veg.
kp
kp
collinsislee
Active Member
kindprincess
Well-Known Member
yep, the 400w's a good one.
babygro
Well-Known Member
It depends entirely on the size of your closet and the efficiency of your ventilation system. A 400w HPS will generate an enormous amount of heat in a small closet area.
Don't be fooled into getting a 400w HPS system just because everyone on here tells you to - they're NOT great in small spaces, where CFL's and T5's CAN offer a better alternative.
kindprincess
Well-Known Member
they are if you can rig a cool tube.... an expensive alternative, but imo, well worth the extra $100+/-. i have a friend who is running two 400w in a 2x6 closet, he does very well.
kp
babygro
Well-Known Member
It's true cool tubes can offer 'some' heat reduction in enclosed spaces, but they're a waste of time, energy and money in terms of the light spread they offer. The internal (or external) reflector on cool tubes is pathetic in terms of the light spread it offers and what you gain by being able to use the cool tube low to the plant canopy you lose in terms of overall light spread.
The other problem with HPS's in cool tubes is the infra red heat emitted, you can ventilate inducted heat - but not radiated and that still goes to the overall heat buildup meaning you still have to have a separate ventilation system in addition to the fan used to cool the cool tube.
It's also more expense on top of the purchase price of the ballast, adding the cool tube AND fan to cool it.
In my opinion cool tubes are a waste of time money and effort and are just a fad.
For closet grows in small spaces a 250w HPS offers a far better alternative to a 400w, if CFL's and T5's aren't preferred.
kindprincess
Well-Known Member
it is true that reflectors on the tubes suck, and i personally don't like to get my lights that close, as it cuts down on the area that is being lit. however, if you leave one end of the tube open, and you're using a strong enough fan (35$ 500cfm inline from hd) you won't have heat issues, not even from radiated heat. you see, light can pass through glass. heat cannot. this is why cars get so blasted hot in the summer with windows rolled up; the light hits objects in the car, and the light is changed into heat, which cannot escape.
with hps, your intesity is much less than the sun, and radiant heat is not a problem. i used to have a pic of my friend licking his 1000w cool tube, but i can't find it.
once again, it comes down to budget and individual preference.
oh, and glass or pyrex cuts approx. 10% of emitted light, so you get less lumens using a cool tube; you make up for it by dropping the light down further.
babygro
Well-Known Member
Nonsense kp, what are you talking about?
How do you think the radiated heat gets out of the bulb in the first place? Yes, the GLASS bulb you claim IR heat can't escape from! Infra red wavelength OR Ultraviolet wavelenghs CAN AND DO pass through glass.
Metal halide bulbs with GLASS tubes emit radiated ultra-violet radiation - I know they emit it because I've seen the spectographs of them - exactly the same as infra-red heat from HPS's.
You might like to have a read of this -
HID's produce light by passing electrical current through different metal vapors, NO coating of phosphor in the way , but only gases which are controllable, safe and reliable can be used. So, the colours (different wavelengths of light) are severely constrained by the limited types of metal vapors that can be used. However, the radiation that is emitted is very INTENSE and often includes copious amounts of Infra Red for you to burn things with, like plant tops.
Now, also consider Infra Red heat is not effected by convection or conduction cooling technology, (electric fans and water cooled"cool tubes") it is radiation, not conduction or convection. This is why the INTENSITY of the (poor light quality) HID lamp can be used to cover large areas, if you bring the lamp too close you will radiate your plants with horrid IR heat, HID lamps and all ballasts must be kept a safe distance away from the plants to avoid IR radiation damage.
Source: PURple for the highest quality
collinsislee
Active Member
my grow space is a closet about 6 feet long and 3 feet deep, im just trying to find the best overall and cost effective way to get 2 or 3 plants growing and able to produce well. thanks for all your comments and thoughts.
kindprincess
Well-Known Member
this is true bg, uv and ir light can travel through glass. but, uv and ir are not heat. they are light. it is only when this light is absorbed that it is transferred to heat energy. the reason bulbs get so hot is because the tube itself contains burning gas that gets very hot. by using a cool tube, the heat that is produced from the burning gasses is sucked out through the exhaust. the reason that the glass bulbs emit heat is that the chamber inside of the glass gets hot, the so does the glass, then the glass becomes a radiator.
now, here's the thing; the light DOES pass through. the heat does not. glass is a very good insulator, and will heat up only when heat builds up inside of an enclosed space. when plants are sun poisoned, it doesn't mean they burnt from heat. they get bleached, kinda like when you go swimming and get a sunburn. it's not from heat.
now, you can acclimate plants so that they don't get bleached by having your lights so close, after all, the sun is much more powerful than a 1000w hps, and plants do just fine outside. it's just a matter of starting high and dropping the lights down a few inches a day.
now, after all this, i'd like to point out that I DON'T USE COOL TUBES. i think they are a waste of light. i'm a big fan of parabolic hoods, and vertical lamps. to me, better spread is more important than intensity.
kp
babygro
Well-Known Member
Come on kp, those people that quote came from MAKE HID bulbs, are you now trying to tell me they're wrong?
Because if you are, we'll simply have to agree to disagree, because I don't agree with anything you've just written, and I KNOW Infra-red and Ultraviolet radiation does pass through glass and Infrared radiated heat IS heat and doesn't just heat up the bulb!
kindprincess
Well-Known Member
i never said that, as a matter of fact, i agreed with you and them.
infared light is a light wavelength. i use ir lights on my lizards. i point the bulb at the glass (and yep, you can feel the heat radiating, these bulbs are designed to emit heat) but, if you move your hand to the inside of the glass tank, you cannot feel the radiated heat at all. you can feel that the glass is slightly warm, but the light itself does not give off any warm sensations. the tank is not tinted in any way.
i'm not saying you're wrong about uv and ir passing through the bulb babe, i'm only trying to say that the heat factor of the lights is combated by cool air passing over the bulb when using a cool tube. it keeps the bulb cool, therefore the bulb does not radiate as much heat. and because the tube is glass, it will also help to insulate and sheild the plants from the heat the bulb puts out. this is why plants can be so close to the tube, there is no heat issue to worry about. the only problem you'll have by keeping the lights under 12'' is bleaching, which i mentioned before.
with this, i call draw. i think if we continue, we'll just be beating the same bush. just know that i agree with you, even if you don't agree with me
love, kp
babygro
Well-Known Member
Our difference of opinion revolves soley around the affects of infra red wavelengths passing through glass and heating things up. Of course IR wavelengths passing through glass not hitting anything the other side isn't going to heat anything up - it's WHEN it hits an object that it creates heat.
Example:
If you turn your microwave on with nothing inside it, nothing will heat up. If you put a glass of water inside your microwave oven and turn it on the water will heat up. It's heating up because of the type of wavelengths being used generating heat within the water.
Now look at how IR wotks from a HPS bulb, the IR passes through the bulb and if it hits nothing on the other side nothing will heat up, however, most of the time you have plant tops in the way and the IR hits them and they heat up in just the same way as the microwave does to the glass of water.
By using HPS bulbs too close to plant tops, (beyond the recommended distances) as I've continually stated on these forums will damage plant tops by Infra red radiated heat.
Now, you also need to understand the difference between INDUCTED heat and RADIATED heat, because from what you've said you don't seem to understand that radiated heat cannot be exhausted away in the same way as inducted heat - because it's RADIATED ! You cannot cool radiated heat with fans, air cooling or water cooling.
Think of it like UV radiation. UV, IR they behave in EXACTLY the same way as they're both radiated. When you sit on the beach with hot sunshine beating down and there's a nice cool wind blowing keeping you nice and cool, do you think that's stopping you getting burnt from UV radiation? Because if you do, try it and see what happens.
The wind will not stop your skin from getting burnt from UV radiation in exactly the same way as an air cooled or water cooled cool shade will not stop your plant tops from getting heated up from infra red radiation.
tckfui
Well-Known Member
Are you saying. that the heat is generated when it meats a surface? be it leaf or wall?
dose it really work like a microwave? with the radiation fucking with the leaves magnetic domains? flipping them every wear and producing friction?... Is that how your saying we get sunburned too? is that true? magnetism gets me burnt?
dose it really work like a microwave? with the radiation fucking with the leaves magnetic domains? flipping them every wear and producing friction?... Is that how your saying we get sunburned too? is that true? magnetism gets me burnt?