Help please
We have two tanks
(a) 500 litres. Established over 5 years. Contains: 4 silver dollars, 3 Salmon Tails, 6 Tiger Barbs, 2 Loaches, 2 Moris, Numerous electric yellows (that breed rampantly), 2 Electric Blues, 2 Red Empress. All are healthy and happy ... EXCEPT for the Red Forest...