Well, mostly okay, huh? Sorry to hear about the Pleco.
Yes, Trident can do air from above the waterline and through the gills.
Maybe if you have an extra air stone put it in the water. Just make sure if there was any injury to his gills or labyrinth organ, he can get as much O2
in whichever way he prefers.
That is a scary situation! It is lucky they all weren't electrocuted to death. Maybe what happened to the Pleco.
Also good you had someone at the lfs
who could get you some solid advice.
I would also just keep up with 2 pwc
's per week instead of one. Maybe even an extra one this week since they were under a lot of stress.
Clean water (always dechlorinated) is key to help them keep their immunity up to fight off illness.