I agree with Johno, hold off on any meds rt now. It they were stressed due to lack of air, and its not been that long since you divided them, just a few days, I would say they might not have digested what you fed them last night... Id hold off on the meds.. Rays can be sinsitive to meds and its not a good idea to give them something they may not need..
Get more air in the tank. add some airstones and go from there. Add them tonight asap and just let them be over night. Dont do anything else.
I would, as long as they have been eating good the last week.. even hold off on feeding them tonight. JUst get them more air, and let them relax.
With your water change and the salt you added. Even though you added water, the salt with the lack of air stones might have shocked the water and used up the air..
So for now, get them some airstones, and supply the tank with more air.
then test you water tonight before bed and see were you are. Tomorrow when you get home, see how they are doing. If they are acting normal, feed them half what you feed them and see if they eat it all up. if they do feed them another 1/4 of the amount you usually do. if they eat that.. then feed the last 1/4
just keep an eye on them... Its not my tank, and Im not there just like most of us, we really cant tell not being there and testing the water ourselves..
So try the air first, and wait till tomorrow to feed.
Hope it helps and keep us posted