Those pics are sooo helpful. I dont think it's limpets. They are more like tiny irregular clumps that sway with the movement of the water. I grabbed my kids microscope it looked like a clump of plant cells?? No movement, looked green. Last time i scrubbed the tank walls, and did large water change spots came back in a day or two.
I took a picture of one of the fish... i dont see any spots... its hard for me to tell if the tail fin has any spots. He survived my initial ich treatment 2 months ago. The other two Tetra do not have any spots. I added them to the tank after I treated ich
My next step was going to be one more scrub... good water change, clean the sponge in my filter (but not the bio-rocks). If that doesn't work... I'm not sure what to do