Planted Tank Guru
Join Date: Feb 2010
Location: Newbury Park, CA
If you can run one bulb then that might work, some ballasts won't work that way though. If you have a burnt out bulb then it might fire up.
Not sure you can cut the lighting period that low and have it work. You want to see the plants and fish at some point!
You could shade the tank with fiberglass window screen cloth. Add more layers until it is the right dimness for low tech.
You could use a layer of floating plants to shade the tank.