I just bought an 8"-9" Black Arowana last night. And I'm thinking of getting a 4"-5" Jardini, and put them together in one tank. Any advice? I have 9 thin bar silver dollar, 1 flagtail, 2 endli bichir, 1 datnoids, 3 parrot fish, 1 pbass and 1 shortbody flowerhorn in my tank. Should I also get an UV sterilizer?