What is this yuck?
I have no idea what this is. It started about a month ago and has taken over everything. I boiled my large rocks today, soaked them in bleach water, tried to scrub it off with a brush and it does not come off. I have no idea what it is. It's red and hard to scrape off of the glass also. I had to throw away 2 large anubias plants as it would not come off. I tried excel, bleach soak, peroxide. Any ideas? It is out of control and I have no idea how to get rid of it. Thanks in advance.