Medication

When it comes to treating pathogens in your aquarium, the right medication can make all the difference. Most medications are available over the counter, with a few exceptions, like antibiotics. In many countries, antibiotics are restricted to prescription use only, and the FDA has recently tightened regulations in the U.S. However, fish antibiotics have found a gray area and are still often available without a prescription. Many common medications for other animals can also be used for fish, although dosing may vary, and I’ll guide you through that as we go.

While obtaining medications for fish isn't as easy as walking into a pharmacy and picking up a prescription, there are a few that are essential to keep on hand for emergencies. Some of the most common medications worth having in your fishkeeping arsenal include:

• Broad-spectrum antibiotics (such as doxycycline for gram-positive bacteria and erythromycin for gram-negative bacteria)

• Praziquantel (for parasites)

• Treatments for ich (such as malachite green, methylene blue, formalin, or copper-based solutions)

• Metronidazole (for protozoan and parasitic infections)

Getting Your Hands on Fish Meds

Praziquantel is one of the easier medications to obtain. It is commonly found as a dog dewormer and is usually kept behind the counter at pet stores. Despite being marketed for dogs, it’s the same chemical used for fish. For treating internal parasites, grind up the tablet and mix it with flake food, as it’s ineffective when dissolved in water. You can also find specialized fish versions like Hikari’s PraziPro, API’s General Cure, and Fritz’s Prazicleanse.

Ich Remedies: Methylene blue, malachite green, and formalin are all effective treatments for ich. These remedies are copper-based and have antimicrobial properties, making them widely available without being controlled substances. Formalin, which is a form of formaldehyde, is particularly effective for treating protozoan infections like ich. Copper is generally safer for fish than formalin and is a more versatile option.

Metronidazole is another useful anti-parasitic medication, often found under brands like API General Cure or Seachem Metroplex. It’s more difficult to find because it has mild antibiotic properties, but its real value lies in its ability to treat protozoan infections and internal parasites.

Antibiotics are the hardest to find but can be crucial in treating bacterial infections. The good news is that antibiotics safe for humans or other animals are also safe for fish, so any antibiotics you can get your hands on are great. API, Seachem and other aquatic chemical manufacturers have lines of antibiotics for fish that can be purchased over the counter, such as API's Erythromycin and Seachem's Kanaplex. The FDA has largely left these fish geared antibiotics alone, allowing their sale without prescription.

Administering Medication 

Administering medication will vary depending on whether you're treating freshwater or saltwater fish and the nature of the disease. For external infections, adding medication directly to the water is typically effective. However, for internal infections in freshwater fish, medications need to be ingested since fish don't drink water in the way humans or mammals do. Their gills don’t absorb larger molecules like those found in medication. Saltwater fish, on the other hand, constantly drink water and can absorb medication directly from the water. Nevertheless, medicated food is often a more effective treatment for internal parasites than simply adding medication to the water.

How to Medicate Freshwater Fish with Food: If your fish need to ingest medication, you can make your own medicated food. Start by grinding up flake food using a mortar and pestle. Then, add the medication (a small amount goes a long way) and a little bit of water to create a paste. Spread the mixture thin, allow it to dry, and then break it into flakes that you can feed to your fish instead of regular food during the treatment period.

By keeping the right medications on hand and understanding how to administer them correctly, you'll be well-equipped to handle most common fish ailments, ensuring the health and happiness of your aquarium inhabitants.