How to Tell If Your Fish Is Stressed (and What to Do About It)
Learn to recognize stressed fish behavior—from clamped fins to color loss—and identify the specific stressors behind each sign so you can act within 24 hours.
Fish
11 articles
A healthy aquarium is a small, balanced ecosystem — and getting it right is more about water and patience than luck. The Fish collection covers tank sizing, cycling, stocking, and the common mistakes that quietly stress or sicken fish.
We base our advice on established aquarium science and aim to set realistic expectations, because the difference between a thriving tank and a struggling one usually comes down to a few fundamentals done properly.
Dive into the guides below to build a tank your fish can genuinely thrive in.
Best Fish for a Beginner Aquarium: Setup First, Species Second
Hardy species won't save a badly cycled tank. Here's which fish thrive in a proper beginner setup—and what that setup actually requires before you bring them home.
Best Aquarium Filter Types Explained (2026 Comparison)
Compare HOB, canister, sponge, and internal filters by turnover rate, biofilter capacity, and maintenance burden—not brand names.
Goldfish Tank Requirements: Why the Bowl Myth Won't Die
Goldfish bowls are still everywhere — and they're quietly killing fish. Here's the tank size goldfish actually need, the stunting science, and why 'hardy' doesn't mean
How to Acclimate Fish to a New Tank Without Losing Them
Complete guide to safely introducing fish to a new aquarium. Learn why tank cycling comes first, which acclimation method to use, and how to avoid the hidden causes of
How to Cycle a Fish Tank Before Adding Fish
Learn the fishless tank cycling method step-by-step. Establish beneficial bacteria safely in 4-8 weeks without killing fish. Includes ammonia dosing and testing.
Axolotl Care for Beginners: What You Need to Know
Axolotl care for beginners requires cool water (60-64°F), a cycled 20-gallon tank, and a carnivorous diet. Learn the setup mistakes that shorten their 15-year lifespan.
How to Reduce Algae in Fish Tank: Prevention & Removal Guide
Learn how to reduce algae in your fish tank by addressing root causes like excess nutrients and light. Prevention-first methods that work long-term.
How to Set Up a 10 Gallon Aquarium (and Cycle It Properly)
A start-to-stocking guide for your first 10 gallon aquarium, including the nitrogen cycle the pet store probably didn't mention. Six weeks to a healthy tank.
Betta Fish Tank Size: Why 5 Gallons Is the Real Minimum
Betta fish can survive in a bowl—they shouldn't. Science-backed guidance on why 5 gallons heated and filtered is the real minimum for betta health and lifespan.
Why Is My Fish Dying? Diagnosis, Action, and When It's Too Late
Your fish is showing signs of distress. This guide walks you through water quality checks, visible symptoms, and realistic next steps — most fish deaths are.