[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

lighting reflectors

I recently set up a 120 gallon planted tank and wanted to pass along my recent experience building light reflectors. 

Background: My 120 gal. All-Glass tank has a wood canopy that houses 4 - 48" (T12) two tube shop light strips. My weekend project was to build light reflectors for the light strips. I was fairly certain that I was not providing all of my light potential to my plants. My requirements were to provide as much light reflection as possible while keeping costs within reason (try to keep this under or around $50.00). I did some research and decided to build my own reflectors after looking around at the reflector kits available from mail order firms. 

I began this project looking around for the least expensive base material. After browsing around Home Depot and Builders Square, I stumbled upon rolled 12" aluminum flashing (this is the stuff roofers use at valleys and such when roofing a house - many widths are available). It turns out that this flashing was easy to work with, was quite malleable, and fairly inexpensive. I spent around $24.00 on a 50' roll. It turns out that I only really needed about 16 feet. Using a rubber mallet, drill, clamps and a couple of good straight edges, I was able to fabricate some really nice reflectors. A nice property of this aluminum flashing is that I could easily cut it with tin snips, autility knife, or even heavy duty scissors. Also, once an edge is creased, the flashing becomes fairly rigid. I found an easy method to crease and fold straight edges by simply laying my work piece flat on the workbench, clamping a straight edge (in my case a straight piece of 1" x 4 " oak) firmly along the my crease line, and used a 4" putty knife along with a mallet to crease the flashing. While the plain aluminum reflectors had good reflective capabilities, I really wanted a mirror finish. After reading the APD archives, I began my search for chrome 'peel and stick' mylar. I called several hobby shops looking for mylar used to cover model airplanes and cars. Most carried it, but the price seemed high - about $70.00 to cover my reflectors. I then tried a sign shop which had rolls of reflective mylar, but they wanted $10.00 a square foot! The sign shop clerk took pity on me and suggested that I try an auto parts store. Taking his advice, I went to Discount Auto Parts and found 16' x 6" chrome mylar 'rocker panel kits'. These cost $14.00 a kit (I needed two) and are quite easy to work with. The mylar is applied to a wetted surface with a squeegee (supplied with the kit), making it really easy to line up and reapply should you make a mistake (which I did a number of times). Once applied and dry a clear protective coating is peeled off revealing
reflectors would have an effect, but the end result was a significant difference. While this tank had fair plant growth prior to the addition of these reflectors, it looks as if I added at least 25% more light and poured a gallon of soda water in the tank. I cannot believe the number of bubbles being generated and the difference of the light level in the tank. Now I'll have to begin watching the demand for CO2 and nutrients.

By the way, this project (start to finish) took about five hours on a Saturday with the 'help' of my four year old son. Also, I was a bit concerned that the rocker panel kit mylar was installed wet, thinking that perhaps the humidity from the tank would loosen the glue. As a test, I took a small piece of mylar covered flashing and left it submerged in water while I took my son to McD's for lunch. When we returned home, the mylar wouldn't budge from the flashing when I tried to peel it off. 

Best Regards,
John Hawkins
Tampa, Florida
jhawkins at ix_netcom.com