I have a 20 long (same footprint just shallower) that had 1 and sometimes 2 T-8 bulbs and was able to grow two types of moss, and banana plant and surprisingly cabomba. The latter had shoots that would reach the surface; the cuttings were replanted. No rapid growth here. Definitely low light.
Bought a 30" dual T5 fixture (bulbs included) for $38 from thatfishplace.com and am able to grow a wider range of plants. Using eco-complete, root tabs, excel, and flourish comp. The 29 is deeper so "your results may vary...". But for the low cost it was an upgrade in my case.