Can you think of any plants in any part of Betta Splendens range that will be okay in 7.6 PH?
Some aquatic plants that grow in betta splendens natural range include:
Rotala rotundifolia (these plants grow like weeds!)
Crinum thaianum (onion plant...I think you can find these at Petco sometimes)
Cyperus helferi (this one apparently grows in more flowing streams whereas bettas live in more slow/still waters)
By the way, not sure about the specific pH requirements but I have grown all of these in my tank and my pH is around 6.5-6.8 usually.
Bettas are not native to rice paddies they are introduced there and native to bodies of slow moving water that is atleast 50 gallons but what did your research turn up?
Sorry, didn't mean to offend any bettas. They weren't really introduced there by man either....they got there through periods of flooding/rain, etc.
The ones I listed above were pretty much it. I have seen some pics of their wild habitat and it is like literally clogged w/ rotala rotundifolia! LOL...so that is what I did for my betta bioptope. (amongst a few other plants I mentioned above)