I've noticed this patch on the side of my tank, and a similar glob on the bottom of my heater. It's like a clear slime/gel. I haven't touched it. In my tank are 2 platies and a snail.
The first picture looks like it's on the bottom of the heater but it's really on the side of the tank.
The first picture looks like it's on the bottom of the heater but it's really on the side of the tank.