Well a mistake is only continual education, assuming it is not continuously repeated....
Repeatedly bringing unquaritened, fish, turtles, crawfish, minnows, drift wood, river rocks, along with Ich, Blue Green algea, Hydra, snails, planar, red worms and tiny water skippers.
The mistake, would only have happened if I drained, and sterilized everything. I still have a few drops of water in my tank from 10 years ago. Along with trace residue of biochar, rusty nails, galvanic corrosion of underwater LED lights, copper sulfate, neomycin, salt, hot water, actinic lighting, and assassin snail shell.
Still looking for some hardy top water feeders that can feed on the water skippers with out jumping out of the tank.