I googled "coral moss" & got several kinds . Do you mean fissidens? Or riccardia, or what? Golly, I hate common names...80F it maybe OK, but some plants are not happy at such a high temp. Why is your temp so high? What fish need that (some do)? Or is that a summer temp? The only way is to try it & see...or that's my technique But I belong to a plant club & rarely have to buy plants...