Juwel Korral 60 (54litre, 60x30 footprint), with supplied heater and basic (sucker feet attchment) filter. No substrate, smallest piece of bogwood in there with two Anubias barteri nana attached.
My adult Pearl Danios have been in there now for ~3 weeks, trying to treat a single protusion on the lower mouth of two of the group of six fish. I went through several meds trying to sort it (Protozin, Melafix, Pimafix) before Myxazin seems to have done the job (did final "day 5" dose today and can see the black outline of where growth was on one fish).
I cannot wait to add them back to the Rio 240 around the coming weekend, they have the two Opsarius to meet as well as the six surviving fry that hatched days after the adults went into QT... Talk about timing!