I have a low tech 10g and its doing pretty well. Without CO2 or ferts and with low lights, there are still plants that will do great.
I have two 9w daylight cfl's. I found in such a small tank, if I went for the 15w cfl's, it rose the water temp. 'Daylight' is important, 6500k-ish.
I used fluorite black capped with gravel. I am not using root caps at this point as I don't seem to need them. I have egeria najas, dwarf saggitaira, asian ambulia, a crypt, bacopa and anubias. You can see my tank in my sig.
I can't offer any advice on the betta sorority, hopefully others will have some experiences to share.
Hope that helps!