Using only one lamp with a parabolic reflector cuts my cost of electricity in half compared to the two tube commercial reflector I was using. The plants are thriving and the single tube provides great downward directed light. Very little light is wasted outside the growing shelf. The light goes straight down onto the plants.
The parabolic collector I am using is based on my design for a solar concentrator. Since the parabola can bounce light in either direction, I am using it here to form a beam of light like a parabola is used in a car headlight. The parabolic mirror bounces the light from the line source (the horticultural florescent tube) into a parallel beam aimed downward onto the plant shelf. It is really quite effective used in this way.
I had written about using one of my four foot parabolic reflectors as a workshop light.
Here I am using the same idea to create a plant light stand out of an IKEA IVAR shelving unit.
The growing season here is short (near Toronto). We can't plant outside until about the end of May so we use a plant stand to start seedlings inside in a warm environment. When they can live outside, they have grown to a good size.
An electrical timer allows us to extend the apparent day length slightly. The plant stand is located next to a south west facing window to catch whatever natural light is available.
The normal large IVAR shelf size is 90 x 50 cm. To create a bit more area on the shelf and to match better the size of the light, I cut a standard IVAR shelf in half and attached these two pieces under the narrow ends of a 2'x4' (122 x 61 cm) sheet of plywood to create a 2 foot by four foot IVAR shelf that matched the parabolic light. I also added some brackets underneath to hard mount the shelf to the IVAR vertical supports for a bit more strength.
The light sits on two horizontal strips of wood that mimic the end of an IVAR shelf.
The pictures are from last year. Since I am moving this year, I won't be growing my own garden plants. We will have a garden but it might be a bit more modest.
When I get settled, I would like to set up this plant stand with an LED light strip. I took this shot of the bottom to show the way I cut the IKEA shelf in half and screwed to the bottom of the plant shelf. I marked the bracket location so that the screws will go back into the same holes. The entire shelf (including the parabolic reflector) will come apart and be packed up flat for the move.
The outdoor LED lights will also get moved.
Thanks for your interest.