How to Treat Sick Fish

Treating a sick aquarium fish can be difficult, especially if you’re new to the hobby or have never seen the disease before. Based on years of experience helping customers at our fish store and online, here are the step-by-step guidelines and medications we personally use to get our fish back to health as quickly as possible.

Step 1: Set up a Quarantine Tank for New or Sick Fish

Newly purchased fish and sick fish have a higher likelihood of spreading illnesses to the rest of your aquariums, so the best practice is to set up a quarantine aquarium where you can first observe the fish for symptoms and treat them with medications if necessary.

Step 2: Proactively Treat New Fish for Diseases

Since it can be difficult to identify which ailment has affected your aquarium, we advise treating new fish (and sick fish with unknown diseases) using broad-spectrum medications for bacterial, fungal, and parasitic infections. After consulting with ichthyologists and spending tens of thousands of dollars in extensive testing, we narrowed down our search to a trio of quarantine medications (i.e., Maracyn, Ich-X, and ParaCleanse) that are safe for all freshwater fish, scaleless fish , invertebrates, plants, and beneficial bacteria. If you do not have access to these drugs, treat with aquarium salt instead, but be careful to remove any plants and invertebrates first.

Step 3: Treat Sick Fish for Specific Illnesses

If you are fairly certain about which disease your fish has, treat for that specific sickness first with the appropriate medication, and follow the manufacturer's instructions on the packaging or their website. Below are links to common diseases and their recommended treatments:

Step 4: Sterilize the Fish Tank and Equipment

After the infections have been treated and the fish have been free of any symptoms for at least 4-6 weeks, you can finally release the isolated fish from quarantine. If you plan on purchasing more fish in the near future, leave the hospital tank running so that it will be ready for the next batch. Otherwise, you can sterilize the quarantine setup and store everything dry.