I'm sure you're right. I'll get some peat and continue with the IAL. Plenty of Oak around, so I'll get some, too. I'll try to emulate the pictures I see of your set-up. Can't do much about the pH. It's already the lowest of all my tanks.
It's just confusing because he became shy over time. Was quite a personality when I first got him.
Honestly, none of my wilds like bare bottom tanks. My persephone looked incredibly pale when they were in a bare bottom grow-out and then when I moved them over into a tank with peat moss as the substrate, the males turned black and blue almost immediately.
It may be a combination of the slightly harder/higher pH water, the lack of substrate and a lack of tannins (sounds like you are not really big on tannins?) is contributing to the shyness.
I wouldn't take out everything but the heater unless you have tannin heavy water and a dark bottom or substrate, as that would most likely be stressful as you've said.
I think give the peat a try. I never even look at the feces of my wild bettas as they live in a semi-feral existence haha and the only health issue I have is with velvet.
All my tanks are bare-bottom. I find it so easy to keep clean and to monitor feces, a task I think important in the keeping of animals....and kids. He has lots of Anubias and Java moss to hide in, plus two pots and a mossball.
I've thought of peat moss (especially as my water is so hard), also oak leaves and IAL. I do slip an IAL in there every once-in-a-while. He rewards me with a bubble nest, but it makes it harder to see for feeding, cleaning and monitoring. I'm going to give it a try, though. My sponge filtered tanks are difficult to keep the pH down in. They might benefit, also. He's not in those; his tank reads 7.4pH.
It's not that he's still shy, it's that he became shy over a period of weeks after a month of behaving like a normal, personable Betta---jumping for food, flaring and hanging out. I thought of taking out all his plants and his filter...just leave him a heater to hide behind. But that sounds stressful for him.
Have you ever thought of using peat moss as a substrate? My wild bettas absolutely love it. I just soak the peat moss in boiling water so it sinks, and then drop a couple handfuls over the glass bottoms of my tanks.
It's odd he is still so shy. I sometimes force my shy fish to interact with me by putting in nothing but the peat moss and a couple of IAL to hide under if they want. Then the only food they get comes from me with my tweezers. Usually that food is a big juicy blackworm just wriggling away.
Unimaculata complex are extremely friendly and my unimaculata are always out. You just need to cling wrap the entire tank, cover that with a piece of bulletproof glass, seal that with padlocks and then brick it all up behind a wall to stop them from jumping out haha.
Yes, I still have the invisible smarigdina. Little is more frustrating than keeping the most beautiful (pet) fish I've ever seen in real life, and rarely see it...and never colored up. And now he's probably too old to breed, so I'm not sure anyone else would want him.
Maybe something in a Unimaculata complex. I want a water-puppy.