Hi I have recently started up a 190 litre aquarium and I am 4 weeks in with no problems what so ever. I have got 6 Neon Tetras, 4 Red Barbed Tetras, 2 Pleco's, 3 Small Catfish, 2 Bala Sharks, 2 Assasin Snails, 1 Shrimp and a beautiful Half Moon Betta. My tank is so peaceful there is no fighting...