rallys, it was looking good. i really think it must have been stress. im reading up on other species now and will do a big watertest to check that again. when i read on certain sites about stingrays, a lot of people do seem to keep plecos with rays. quite strange?
Rays are very sensitive to water parameters and especially if already stressed out from capture/shipping and new habitat/water.
Even if they are eating, not obviously parasite infected and seemingly happy, fluctuations in water can be the last straw.
Floating is a bad sign... Curling is the bells tolling, 99% goner, they don't call it the "Deathcurl" for nothing
Don't feel too bad, I understand the mortality rate can be high if their not sold already conditioned to captivity and in top health.
It could've been something very minor that tilted the scales...
Bummer!