It's leftover from double sided tape from the old background (flipped tank when I painted itHa ha.
Never heard a fish keeper blaming missing a disease on residue on the glass
Classic
MariaS,
Why suggest metro for treating external worms?
Metro is a type of anti-biotic. Bacterial infection, flagellates, microbes.
Doubt it will work on the worms?
Seachems site says that it is safe for invertebrates. Basically not ideal?