Pexels/Tuan Vy Skipping fish quarantine is the top reason tanks crash. Learn how to set up a simple, effective quarantine system to protect your entire aquatic community. April 18, 2026 The Heartbreak You Can Avoid Imagine this: you've spent months carefully cultivating a peaceful, vibrant community tank. Your tetras school in perfect harmony, your corydoras scavenge happily, and your prized centerpiece fish is thriving. Then, you add a stunning new fish from the store, and within two weeks, your entire tank is a disaster zone.