Low light for a 29 gallon

I made a lengthy post on what I have been dealing with in my 29 gallon tank, so I won't repeat all of that here: http://www.plantedtank.net/forums/showthread.php?t=573354

However, I understand that the stem plants that were growing great in my 20 long are/were suffering in my 29 gallon tank because my light is low. I actually have a 48" shop light fixture hanging over the top glass with one T8 bulb running in it. I experimented with running both, but it seemed that my algae problems would worsen when I did this. Now that I'm running just one, I have no significant algae problem, which is tremendously important to me, especially since I had some dreaded furry algae before.

I realize that this sort of setup is low light, and won't work for many of my stem plants. I've actually started up some emersed pots to house some of those. However, will one T8 over a 29 gallon likely be good enough to continue growing anubias, moss, some kinds of cryptocoryne, and java fern? I'm currently successfully growing anubias, java fern, a small sword plant, crypt petchii, valisneria, and floating pennywort.

This is a non-CO2 tank. I had been running DIY, but found out that my diffusion system was non-functional. The bulbs are 5000K and they are old, but I do not know exactly how old. I probably need to replace them.

I realize that I could run two T8 bulbs by raising the fixture higher above the tank, and if this would make a significant improvement in the lighting, it might be worth it. However, if I could only raise it a few PAR before hitting the algae threshhold again, I wouldn't consider the increased power consumption worth it, and would rather stick with one tube. I haven't done much experimentation with running two tubes high above the tank.