I had four fish, im down to three, i had a black moor(that died due to whiotespot), now i only have two calico fantails and a blue oranda. one of my calicos look completey fine and unaffected whilst my other calico looks worse even though i am treating them, and my blue oranda had fin rot which i have treated and he's starting to look better slowly. the problem im having is my blue oranda keeps chasing my ill calico around the tank nipping at its belly and sides. so anyone know whats going on and what i should do? please help?

btw my blue oranda only chases the infected calico fantail.

Hi there,

First of all, before we go any further, can you provide us with the following info?

• Water conditions (pH, ammonia, nitrite and nitrate); an aquatic store will be able to test a fresh sample of aquarium water if you don't currently have a test kit available.
  
• The size of the tank (volume in litres or gallons, or dimensions).
  
• Filtration type.

In 9/10 cases diseases in fish are caused by poor water quality. This can be due to overcrowding, insufficient filtration, an uncycled filter, overfeeding or a lack of maintenance on the aquarium.