Have 3 goldfish in a 20 ltr tank(2 black 1 gold). Noticed in the last week that the gold one has been acting strangely. One minute he's on the bottom hiding behind stuff then he's at the top like he's...
i have just removed sludge from the garden pond and the water is all muddy brown. How do I clean it. you cannot see anything. The filter has been running for two days now, with no improvement.