Hi all, I am brand new to this site but not new to fish keeping. I have recently ventured into keeping freshwater stingrays and have a 6x3x2 indoor pond for them but I have recently acquired a marbled motoro female and a male motoro who are in QT who has these lines shaped in a circle on them. I think they're parasites but have not confirmed that. Currently I have done the recomended dose of prazi pro for a week and that didn't work so I gave them a few days rest and have tried ocean frees product for lice, anchor worms, etc. I have not used salt yet (waiting for salt meter to come in) but I heard salt at .3% along with prazi at a triple dose does wonders. Does anybody have any suggestions or have any of you experienced ray keepers seen this? My levels are all fine. Ammonia 0, nitrites 0 and nitrates around 5 or less.