I just wanted to point out that when the front legs pop out, the morphing tad/frog is converting its gills to lungs, so it will need someplace to climb out of the water or it could drown. As it develops, you might want to lower the water level and have a rock or some moss for it to climb onto.

My son and I rescued three similar tads from a pool of water that was drying out and pump them in a decent sized lined pond we built this spring for some goldfish. I was thrilled a month or two later to see a couple of small bullfrogs hanging out on the shore. They are pretty shy and jump in the water if we get close.

Oh, and welcome to the forum.