Update: I got some new pics so you can see better. I had to put him in a bowl while I was doing something and decided to get some pictures while I was at it. You can see the trouble area much better now. A water softening pillow is in the filter and I'm looking into order some IALs. Also, I tested the water this morning and the pH is now perfect and the gH is soft. Great water quality in general after putting in the pillow.
I do worry that he bites after you said that :( I feel like I'd see it seeing as I'm at my desk/computer 8-10hrs mon-sat and the aquarium is right next to it. I'm really worried about him.
( I'm thinking about making the aquarium blackwater actually. From what I've researched it shouldn't harm the frogs any. )