If you fish is suffering from body fungus, body reddening, cotton fin, cotton mount, fin reddening and other fungal infections, then you can treat them with the API Pimafix.
If you notice that using this anti-fungal treatment is making your tank water appear bubbly, foamy, cloudy or milky, then you can take a look at this guide from Aquarium Blueprints to see what actions you can take to clarify your aquarium.
1. The first step we recommend taking is to observe your pet fish to see if there are acting strangely. In particular, you need to observe if there is any body twitching, head twitching, sudden and erratic darting around the tank as well as gasping for air at the top of the water surface.
If you see these strange behaviors, then it is likely that you overdosed Pimafix into your tank water.
2. If you fish appear to be acting normally, then we recommend completing your treatment before addressing the cloudy water issue.
For the uninformed, API recommends that you dose Pimafix every day for 7 days. On the 8th day of treatment, you will then need to do a 25% water change.
In terms of dosage, you should add 5 mL of Pimafix for every 20 gallons in your fish tank. If you are using liters to measure your tank water volume, then you need to dose 5 mL of Pimafix for every 38 liters of aquarium water.
3. After completing the treatment as instructed, you can then start addressing the bubbly or cloudy water in your fish tank.
The best way to clarify your tank water is by adding activated carbon in your fish tank filter. This chemical filter media will absorb any remaining Pimafix as well as other impurities, in your tank water. As a result, the cloudy or milky water should go away over time.
4. If you want to clear your fish tank water as soon as possible, then we recommend doing daily water changes. By doing so, you will further dilute Pimafix from your aquarium in addition to help getting rid of any impurities.
By adding activated carbon in your filter and doing daily water changes, you should be able to eventually get rid of the cloudy or milky water in your fish tank.