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You'll get a picture of the koi/goldfish, you click on the koi fish where it's sick, or choose from several other behavioral options that your koi may be exhibiting.

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We offer FREE personal help with your sick fish and/or pond water quality problem. Fill out our easy “Help Form” by Aqua Meds

Feeding Koi

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Aqua Meds®

Have questions about care of sick fish and/or pond water quality problems and how to treat them? We have the answers.

Fish Medicines

Learn about fish medicines, what they do, and where to get them.


If you have a koi, pond or fish problem, this site takes you through twenty easy questions and at the end you know what you need to fix in your pond to create restored Koi health.




Argulus Koi Fish Lice "Argulus" is a crustacean or branchiurian parasite most commonly encountered in koi ponds, but they are also found in aquaria. They are easily detected when they strike. Fish lice are greenish disc shaped organisms with suckers and small legs. Fish lice even have a pair of eye spots on the anterior end. They spend their time darting around in the water away from, and also directly on your koi. Fish lice lay their eggs in tubular structures on the glass and ornaments. Fish lice are not micrscopic, they can be seen on your koi unlike most koi parasites. 

Fish lice can be very destructive to your koi.

Fish lice carry Aeromonas and other bacteria on their feeding stiletto and thus infect each koi  they bite.

Treatment for fish lice is by the application of: Diflubenzuron.