After seeing many of the same questions asked I thought I'd put something together in a thread for all new growers looking to add a parabolic reflector to there grow
What is a parabolic reflector
A Parabolic reflector is an umbrella shaped reflective surface used to Project light in and around the grow room. This comes in many different forms such as size, shape, horizontal or vertical bulb and a White or silver surface.
White or Silver what's the difference?
Ive seen this question asked a lot and wasn't sure on an answer myself so decided to do some searching and found that the White surface gives better light scattering. Light scattering is a deflection of a light Ray from a straight path. The silver surface makes for better light retraction.Light retraction is the bending of a light Wave when it enters a material. Both silver or white will perform equally with plenty of light spread so I guess it's just a case of which you prefer or can get hold of at the time. Here's an example of both :
Light spread compared to other shades
All grow light reflectors work well in there own way. For example barn style, Adjustawings, air cooled and parabolics. Here's a diagram showing the light spread between each shade :
Reflector sizes
Most parabolics come in sizes of 80cm or 100cm. The 80cm allowing up to a 400w bulb and the 100cm up to a 1000w. These come flat packed so grab yourself a Phillips screwdriver a socket/spanner set, tea coffee or beer and last but not least a spliff and your ready for the assembly ordeal.
If your growing in a tent of a similar size such as a 1.2m and planning on using the 100cm version then the two things to bare in mind are negative pressure and height . You soon lose the 0.2 space you have around the shade once the tents zipped up. An easy method to prevent this is to attach tight bungee cords from pole to pole this will prevent the tent pulling in under negative pressure allowing more heat to escape around the shade. Also when using a carbon filter and shade you lose height due to the shape of the shade. So plenty of Lst will help.
Temperature and Light distance
When I first added a para into the groom I noticed an overall temp drop of around 4-5c compared to the previous barn style reflector. This is down to the bulb being vertical which in turn spreads the heat evenly causing less hot spots. There is vents in the top but an additional mod is to bend the tops of the panels on the shade to allow gaps around the bulb for more heat to escape up into the extraction allowing you to bring the shade much closer to the plant tops helping towards a nice even canopy and good light penetration.
Heres a couple of pics showing the parabolic in action in a 1.2 tent.
Thats all folks
Please feel free to add any other parabolic information or pictures to this thread
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