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Our Diagnosis

It sounds like your fish are a bit under the weather

How to be sure

Your fish may not have any obvious physical symptoms. They may appear pale or dark and shimmy, scratch, jump and flick against objects in the pond but you don’t know what is specifically wrong. Rapid gill movement and breathing at the water surface are also signs of your fish’s discomfort.

Step 1 – Treat your fish

  • Treat the entire pond using All in One Treatment, you can calculate the correct dosage here.
  • Also dose with Pond Guardian Tonic Salt to help support your fish’s immune system.
  • Observe the recovery and follow any re-treatment advise on pack or on our dosage calculator page.
  • Finally, give your fish some time to recover. Avoid excessive cleaning or adding new fish.

Remember to remove the carbon from your filter prior to dosing with treatment.

Step 2 – Check your pond

  • When fish are sick, always test your pond 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. Carry out any maintenance needed, or replace faulty or broken parts.
  • Adding aeration will also help support fish while they are unwell.


Blagdon fish medications can safely be used with Blagdon water and algae treatments.

If you want to re-dose, or change a fish medication, wait 7 days before beginning the new course.

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