hi there , if the water is unheated and you haven't put any other medication in the pond , i would recommend salt at the rate of 1kg per 100gals, the flashing might be caused by raised nitrite or changes in the ph , check them both , but don't panic salt is a great tonic and if all your readings are fine things will settle down . p.s the kids put a yellow plastic duck in my pond and the fish went mental for days after .. good luck stephen walker
Posted on Jan 22, 2008, 7:03 PM from IP address 86.160.203.49