Don’t panic — ich is one of the most common and treatable fish diseases. Almost every fish keeper deals with it at least once.
What causes ich?
Ich is caused by the parasite Ichthyophthirius multifiliis. It has a complex life cycle: the spots you see are embedded under the fish’s skin, but the parasite is only vulnerable to medication when it’s free-swimming.
[Placeholder body — full treatment guide coming soon.]
Prevention
The best defense is a stress-free environment: stable water parameters, proper temperature, and quarantining new fish before adding them to your main tank.