How big is the tank with the betta in it? I have 2 young clowns in with 6 bettas. The clown will spend most of the time hiding in or under things. The bettas usually don't venture down to the bottom of the tank unless they are the algae waffer. Supposedly they are aggressive with their own species and seek out their own territiry but I always see these two within 2-3 inches of each other. I added some ciclid stones for extra hiding spots. Its more natural looking then the PVC pipe that is recommended. I also added a sillicon anemone type thing that they seem to love. Plus I have real plants if they ever venture out away from the corner of the tank
What else have I learned..ummm..yes. You need to have wood for them, not only to hide in but it's part of their diet. I had a chunk of mopani and 4 small sticks of cholla wood (which I think is actually from a cactus and not from a tree at all.) And they poop alot - like snails so either have good filtration or up the gravel siponing. I never see the plecos - just their trail of poop
. I added an airstone too since I had a small airpump. I honestly don't know if i need it or not. Alot of the info I see is conflicting which I find infuriating
I think that aslong as the tank is big enough - ie, not a bowl - and you have some ground cover and some wood, the pleco should be fine with the betta.