So yesterday I added a pair of savini(3-4") to my 125 gallon CA cichlid tank with 4 young cubans(2-3") and 4 young firemouth cichlids(3"). The night I added my salvini the cuban started sulking at the bottom of the tank and seemed incapable of using it's tail fin. I moved him to a 29 gallon that I have running underneath the 125. He also seems to be gasping pretty heavily but he is still able to move just not his tail fin. His swimming pattern has gotten a bit erratic. My other fish are doing perfectly fine so far. What should I do? The parameters in the 125 and 29 are identical with ammonia at 0, nitrite at 0, and nitrate at 10ppm. I do 50% water changes weekly and the tank(125) is running a aquaclear 110, rena xp2, and an emperor 400 I believe(I know not the best filtration, im trying to get more). What should I do to help my little cuban? I don't want to loose him.