I think you're right chem. That's what I thought too.
If you do buy a double strip and get some decent bulbs you shouldn't have any problems growing plants. I would say with 40 watts over a 29 gallon you should be able to grow many types, but some need more light than that obviously. As for the hygros, you may have thrown them out for no reason. The leaves often come back as long as the stems are fine. They just need to grow new submerged growth.
If you do buy a double strip and get some decent bulbs you shouldn't have any problems growing plants. I would say with 40 watts over a 29 gallon you should be able to grow many types, but some need more light than that obviously. As for the hygros, you may have thrown them out for no reason. The leaves often come back as long as the stems are fine. They just need to grow new submerged growth.