It sounds like your fish has Carp pox or Lymphocystus virus
How to be sure
These infections give your fish white, grey or pink, waxy looking, pin prick-like growths and bumps on its fins or skin. Although they are not usually life threatening, they could still make your fish feel poorly and run down. These viral infections are not directly treatable, although supportive measures will help your fish feel better.
Step 1 – Treat your fish
- Remove the carbon filter out of your filtration – but don’t forget to return it 7 days after the last dose.
- Treat the tank with Disease Away to help support the fish and aid their immune system, you can check the correct dosage for your aquarium size here. Do not use with scaleless fish or invertebrates.
- Also dose with Aqualibrium First Aid Salt – it helps boost your fish’s ability to fight the illness.
- Give your fish some time-out to recover – avoid excessive cleaning, re-decorating or adding new fishy friends.
- To re-treat, or treat another problem, follow the on pack guidelines for using more treatment.
Watch Out! – Treatments can sometimes reduce oxygen levels in the water. If you see fish gasping at the surface, you can increase oxygen by adding an air pump.
Step 2 – Treat your aquarium
- When fish are sick, always test your aquarium water for excessive ammonia, nitrite, nitrate or pH imbalance.
- Treat any unhealthy results to rebalance your water quality and give your fish the best chance of getting fighting fit again.
- Check all your equipment is working properly – especially filters and heaters (check your aquarium temperature with your thermometer). Carry out any maintenance needed, or replace faulty or broken parts.