Cool hood v parabolic hood v euro reflector
Ive been asked a few times what i think is the best reflector for HID lighting so i thought id do a post on them and my experiences. Ive only used a DE (double ended Bulb) type HID once so ill focus on single ended standard HID shades that take (HPS High Pressure Sodium lamp) and MH (Metal Halide lamp).
The main types of reflector for HID ( High-intensity discharge lamps) are your standard reflector Euro barn style or adjustawing style, Cool hoods and cool shades and Parabolic reflectors. Ive used all 3 and 1 is a clear winner from many grows in my experience.
Euro barn Adjustable standard reflectors
Pros:
Cheap.
Cover well enough.
Good penetration.
Cons:
Hot spot.
Heat.
While coverage is ok you can get much better.
These types of shades are ok, they get the job done and have done for many years. My biggest issue using these is the heat and uneven coverage. The intensity of the light directly under the light is much more than further away at canopy level. This means you can not get these lights very close to the tops of the plants and evn if you could the heat directly below will cause more issue. If on a budget these will do a good job but there are better options.
Cool hoods and Cool tubes
Pros:
Cool running.
On cool hoods the coverage can be amazing in larger models, not cool tubes.
Good penetration.
Cons:
Lot of kit needed to run correctly.
Hot spot for light intensity.
Loss of lumen output because of glass.
Poor coverage on cool tubes.
Noisey.
First off... Do not waste your money on cool tubes if going for a cool shade set up, the coverage is terrible. As for Cool hoods or cool shades as they are also called they are very good in larger sizes. To date my best weight from a grow was using one of these. I had the Goldstar XXL hood 50 x 60cm. This shade had an amazing spread of light over 1.2 x 1.2m tent. The main reason anyone looks at these shades is to reduce heat but imo and from results they are heads and shoulders above standard style reflectors for many reasons.
The main downside to these types of reflectors is the kit needed to run them properly. You will need to run these inline with your current extraction set up but it will reduce the airflow by quite a bit or run them on a separate fan. These are also noisy running, all the ducting and air movement will add to the noise of your set up.
A tip when using these is to blow air through them, not suck through them. The main reason for this is pulling air through them creates negative pressure, because of all the joints in ducting to shade and sometimes the quality of the shade itself they can develop slight leaks. Having positive pressure running through the system pushes air through the leaks inside the grow space, doesn't suck them in and then out of your exhaust which will put hot smelly air where you dont want it.
These also suffer from the same issue as standard reflectors with a "hot spot" from light intensity. While heat will be greatly reduced compared to a standard type reflector the intensity of the light is till there. You can get these closer to your canopy but the bulb itself can cause light burn if to close and the coverage again drops off as you move away from directly under the light.
If going for a cool set up stay away from cool tubes!
Parabolic shades
Pros:
Even coverage.
Cool.
No hot spot.
Cons:
Penetration is not as good as the above 2 reflectors.
Parabolic shades are by far my favourite style of reflector. In my opinion they run as cool as cool shade set ups with no extra kit. The light spread on these is perfectly even and the sizes they come in mean you can virtually cover your grow space with even light. Because these use a vertical bulb you are able to get these much closer to your canopy without suffering light burn. The heat is evenly spread to meaning you can almost sit this on top of your plants. The light itself is a lot less intense which causes the only draw back to these lights which is light penetration through the canopy to lower growth.
I measured the output of my parabolic shades versus a standard reflector using a basic umol reader once and the umol reading directly under the bulb on the parabolic was about a 3rd less than the standard reflector. The difference is the reading was almost identical over the whole grow are from the parabolic, the standard shade dropped umol reading a lot as i moved the phone away from the center of the grow tent.
So using a parabolic gives me a even spread of light over the whole tent. Its not as intense of a light but i can get this shade inches from my canopy whereas i have to have a normal shade 12-18 inches from canopy level. The parabolic is as cool as a cool shade, requires less kit. Its a winner for me. Ive run the same strains under all 3 types and quality and yield are very close between cool shades and parabolic shades, less kit and possible issues are what makes the parabolic reflector my go to HID grow light.
Ive been asked a few times what i think is the best reflector for HID lighting so i thought id do a post on them and my experiences. Ive only used a DE (double ended Bulb) type HID once so ill focus on single ended standard HID shades that take (HPS High Pressure Sodium lamp) and MH (Metal Halide lamp).
The main types of reflector for HID ( High-intensity discharge lamps) are your standard reflector Euro barn style or adjustawing style, Cool hoods and cool shades and Parabolic reflectors. Ive used all 3 and 1 is a clear winner from many grows in my experience.
Euro barn Adjustable standard reflectors
Pros:
Cheap.
Cover well enough.
Good penetration.
Cons:
Hot spot.
Heat.
While coverage is ok you can get much better.
These types of shades are ok, they get the job done and have done for many years. My biggest issue using these is the heat and uneven coverage. The intensity of the light directly under the light is much more than further away at canopy level. This means you can not get these lights very close to the tops of the plants and evn if you could the heat directly below will cause more issue. If on a budget these will do a good job but there are better options.
Cool hoods and Cool tubes
Pros:
Cool running.
On cool hoods the coverage can be amazing in larger models, not cool tubes.
Good penetration.
Cons:
Lot of kit needed to run correctly.
Hot spot for light intensity.
Loss of lumen output because of glass.
Poor coverage on cool tubes.
Noisey.
First off... Do not waste your money on cool tubes if going for a cool shade set up, the coverage is terrible. As for Cool hoods or cool shades as they are also called they are very good in larger sizes. To date my best weight from a grow was using one of these. I had the Goldstar XXL hood 50 x 60cm. This shade had an amazing spread of light over 1.2 x 1.2m tent. The main reason anyone looks at these shades is to reduce heat but imo and from results they are heads and shoulders above standard style reflectors for many reasons.
The main downside to these types of reflectors is the kit needed to run them properly. You will need to run these inline with your current extraction set up but it will reduce the airflow by quite a bit or run them on a separate fan. These are also noisy running, all the ducting and air movement will add to the noise of your set up.
A tip when using these is to blow air through them, not suck through them. The main reason for this is pulling air through them creates negative pressure, because of all the joints in ducting to shade and sometimes the quality of the shade itself they can develop slight leaks. Having positive pressure running through the system pushes air through the leaks inside the grow space, doesn't suck them in and then out of your exhaust which will put hot smelly air where you dont want it.
These also suffer from the same issue as standard reflectors with a "hot spot" from light intensity. While heat will be greatly reduced compared to a standard type reflector the intensity of the light is till there. You can get these closer to your canopy but the bulb itself can cause light burn if to close and the coverage again drops off as you move away from directly under the light.
If going for a cool set up stay away from cool tubes!
Parabolic shades
Pros:
Even coverage.
Cool.
No hot spot.
Cons:
Penetration is not as good as the above 2 reflectors.
Parabolic shades are by far my favourite style of reflector. In my opinion they run as cool as cool shade set ups with no extra kit. The light spread on these is perfectly even and the sizes they come in mean you can virtually cover your grow space with even light. Because these use a vertical bulb you are able to get these much closer to your canopy without suffering light burn. The heat is evenly spread to meaning you can almost sit this on top of your plants. The light itself is a lot less intense which causes the only draw back to these lights which is light penetration through the canopy to lower growth.
I measured the output of my parabolic shades versus a standard reflector using a basic umol reader once and the umol reading directly under the bulb on the parabolic was about a 3rd less than the standard reflector. The difference is the reading was almost identical over the whole grow are from the parabolic, the standard shade dropped umol reading a lot as i moved the phone away from the center of the grow tent.
So using a parabolic gives me a even spread of light over the whole tent. Its not as intense of a light but i can get this shade inches from my canopy whereas i have to have a normal shade 12-18 inches from canopy level. The parabolic is as cool as a cool shade, requires less kit. Its a winner for me. Ive run the same strains under all 3 types and quality and yield are very close between cool shades and parabolic shades, less kit and possible issues are what makes the parabolic reflector my go to HID grow light.
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