hi guys i currently have 4 wild discus in a 140 liter aquarium with an ehim canister filter i am planning on upgrading to a 210 gallon aquarium with a 200 liter sump i know the sump is big but i want good filtration and i was wondering whether Atlantic stingrays can live with discus altums tetras i still have school and i dont know if stingrays need a lot of work by the way i use ro water so its no problem the water quality i do weakly 50 percent water changes and i have nitrate resin in my filter would there be better stingrays to keep in a 210 gallon aquarium by the way i am new to this website so i hope i am not doing anything wrong