if it is straight from ORA, i don't QT. they keep a clean facility, they have too or they'd lose hundreds of thousands of fish. if it is CB from a LFS i look at what other fish they are housing on the same system. a certain store i frequent often has WC on the same system as ORA, i QT the ORA in that case. the WC often are showing signs of brook. i have brought this up to them a few times and i think they are looking at different options to keep ORA seperate from WC.