Love your frog- such a cute little guy. I had a plating sponge from Gulf Coast in the cart yesterday, but decided not to pull the trigger because of it’s origins. Trying to stick to my biotope as long as I can lolCool tank! I wanted to add sponges too, but I was scared to lose them and poison my tank. A local hobbyist has a photosynthetic plating sponge, which I might snag a piece of, just because I love sponges, and I think this would be a good first step. I have a barebottom tank because it's easier to maintain, but I don't love the look so I may end up changing it eventually. I think macros are a super cool choice for the tank- I only have chaeto, but I don't love the look of that in the tank, so I'm thinking of getting some pom pom gracilaria from algae barn, but they're sold out. I want something that my angler could perch on, but it's tough to find rigid fast-growing algae in my experience.
If you live in the states and are looking for a great place for macros, I’d definitely recommend Gulf Coast or KP Aquatics (expensive shipping with KP).