When asked for parameters, numbers/exact answers, not descriptions are useful, as is providing all of the requested information. So "upper 70's" (sic) is less useful than 78. Typically, "parameters" include ammonia, nitrite, and nitrate readings, always, and in some cases pH is useful, although that's usually less relevant with captive bred populations.
For what it's worth, your cory will be much less stressed with a school.
Chinese algae eaters, if I'm recalling species correctly, have been known to suck off slime coats on disc shaped fish.