ya know i did find 1 white worm thingy .. bright white, about 3/4" long just swimming around... well with 10k gph, more like getting blown around
if anyone was awake they would have eaten it
i do have crabs. 1 about the size of a nickle it is black and white and horny and lives in my birdsnest
the other is an acro crab... sort of homeless and I catch him cruzing around waiting for me to get a big colony for him