Over the past few years the family has started seeds for our garden. We have tried a few different enclosures from store bought, to floating the starting tray in our fish tank. (it works if you don't sink the tray with the filter) The biggest hurdles were light and temperature. Our house has a programmable thermostat and in front of the door wall is the sunniest but not the warmest.
So last year after killing off the first set of seeds, I made a seed starting box, with lights, air flow, and heat (from the lights). The plants thrived.
Here is how its made...
Step 1: Materials
1 Sterlite clear plastic container.
3 temporary bulb holders (home depot rubber coated) UPC # 0 78477 83939 1
3 CFL 13w light bulbs (do not use other types the heat would create a dangerous situation)
2 wire nuts
1 cord end (I got this one off a dead microwave) a short extension cord work well also
3 band ties
double sided tape
piece of bubble wrap the size of the bottom of the container
hole saw (the size of the bulb holders) 1 1/2"