Well they both look healthy to me. Just to be safe, keep the water as clean as possible (pristine). I'd do 100% water changes every day for a week and add some aquarium salt (not table salt) to the water for just those 7 days. Since I don't see a particular ailment, I'd follow the instructions on the box (usually 1/2 tsp per gallon). Afterward, if you think their condition looks worse or something happens, post again with pictures and we'll give you our answers.
As for now, keep those tanks clean!
Note: Treat the water with water conditioner / other additives you use before adding it to the tank...chlorine in tap water can kill your fish. Also make sure you acclimate them each time.