Out of all the space he has to himself in the 10 gallon tank, my betta seems to enjoy it best either leaning against the intake tube or fighting the current beneath the output. I've baffled the filter so much there's as little current as possible but he's determined to go right beneath what current there is and fight his way upward.
His fins are split, from either the last filter or maybe the lava rock I realized had sharper parts than I'd originally found and so I removed it. I'm afraid he's stressing them more this way and they won't heal.
The filter is an Aquaclear 20, on it's lowest setting and stuffed with filter sponge in the output. The water that goes through is trickling but right beneath there's still a minor current. I just bought this filter due to what reviews I found on here and due to the fact I could adjust it.
Maybe he's just not cut out for a filter... I might just get a smaller tank for him.. but it makes me sad due to not wanting to have him in a small 2 gallon.. and all the money I spent to set up a perfect tank for him..