I agree with jclee-mine would float until something would startle them and they would shoot down, hide for a bit, and then swim back up and do it again. I put a fake plastic floating plant with broad leaves on top and the frogs would love to hide and chase each other under the leaves! As long as he is eating and is still startled if you reach out to touch him or something happens nearby, I am sure he is fine.

jclee-when I had ACFs, the bigger they got, the less their whole bodies would float at the top. Instead, they would do what I called the "Zen Hug": up on their tippy toes on their back legs, standing straight up, with their front limbs spread wide open. It was very cute. Or, now that I think about it, maybe they were begging for more food??? Lol