Saltwater Fish Disease & Treatment Quick-Reference
Even with great care, saltwater fish sometimes get sick. At Tropical Treasures in Cheyenne, we always remind folks that catching problems early makes all the difference. This quick-reference covers the most common diseases, what they look like, and how they're typically treated — but it's a starting point, not a substitute for proper diagnosis.
Marine ich (Cryptocaryon) 🦠
Look for tiny white salt-grain spots on fins and body, flashing, and rapid breathing. It's the most common saltwater parasite. Treatment usually means moving fish to a quarantine tank for copper or hyposalinity therapy — never medicate your display reef.
Marine velvet (Amyloodinium) ⚠️
More dangerous and faster-moving than ich, velvet gives fish a fine gold or dusty sheen, heavy breathing, and clamped fins. Fish may die quickly. It also needs quarantine treatment with copper, and speed matters — act at the first sign.
Bacterial infections 🧠
Frayed or rotting fins, red sores, cloudy eyes, or open ulcers point to bacterial issues, often secondary to stress or poor water quality. Improving water conditions plus an appropriate antibacterial in quarantine is the usual approach.
Prevention beats treatment 🛡️
Most outbreaks start with a new, un-quarantined fish. Quarantine every new arrival, keep stable water parameters, feed a varied diet, and avoid overcrowding. A healthy, low-stress fish fights off problems far better. See our quarantine tank guide for setup steps, and browse test kits and supplies or call 307-369-1118.
When should you act? 🤔
If you see spots, labored breathing, or unusual behavior, isolate and observe right away. Velvet needs immediate action; mild ich on an otherwise healthy fish can sometimes be managed with careful quarantine. When in doubt, ask before medicating.
The bottom line ✅
Catch problems early, quarantine new and sick fish, and never dump medications into your reef display. Healthy water and a good quarantine routine prevent most disease. Have a sick fish and aren't sure what it is? Stop by Tropical Treasures in Cheyenne or call 307-369-1118, and find more help on The Tank Buddy Blog.