Blog
Why Are My New Aquarium Plants Melting?
New aquarium plants often melt within days of planting. Here's how to tell normal transition melt from an actual problem, and what to do about it.
Aquarium Plants Not Growing? It's Probably Light or CO2
Stalled or stunted aquarium plant growth is almost always a light or CO2 limitation. Here's how to tell which one, and the fix for each.
Holes in Aquarium Plant Leaves: Causes and How to Fix Them
Holes in aquarium plant leaves, including Anubias and Java Fern, usually mean a potassium deficiency, not pests. Here's how to spot it and fix it.
Algae on Aquarium Plant Leaves: How to Remove It and Stop It Coming Back
Algae growing directly on plant leaves points to a light/nutrient imbalance. Here's how to clear it and stop it from coming back.
Why Does My Fish Tank Smell Bad?
A bad-smelling fish tank almost always means decaying organic matter or a bacterial imbalance. Here's what to check and how to fix it.
Fish Hiding and Not Eating? Causes and What to Do First
A fish hiding and not eating is usually the first sign of stress, bullying, or early illness. Test your water first, then check these causes.
Why Are My Fish Fighting? Signs, Causes, and How to Stop It
Fish fighting is usually a stocking problem: too little space, the wrong tankmates, or too few hiding spots. Here's how to tell and how to fix it.
Fish Died Suddenly? What to Check Before Adding More
Occasional fish loss can happen from old age, but test your water before restocking. Here's what to check after losing a fish.
Brown or Tea-Colored Aquarium Water: Causes and How to Clear It
Brown or tea-colored aquarium water is usually tannins from driftwood or leaves. It's safe for fish, and activated carbon clears it if you want.
Foam or Bubbles on Your Aquarium Water Surface
Foam or bubbles on your aquarium's surface usually mean a buildup of dissolved proteins from overfeeding or waste. Here's how to clear it.
How to Know if Two Fish Species Are Compatible
Fish compatibility depends on adult size, temperament, water parameters, and tank space together. Here's how to check before combining species.
Why Is My Fish Gasping at the Surface?
Fish gasping at the surface almost always means low oxygen or an ammonia/nitrite spike. Here's how to tell which, and what to do in the first 10 minutes.
White Spots on Fish: Is It Ich? Symptoms, Causes, and Treatment
Small white spots like salt or sugar grains are the classic sign of ich. Here's how it spreads, how to treat the whole tank, and how long it takes to clear.
Cloudy Fish Tank Water: Causes and How Long It Takes to Clear
White or gray cloudy tank water is usually a bacterial bloom. Here's what causes it, whether to do a water change, and how long it takes to clear on its own.
How to Cycle a New Fish Tank (Fishless Cycling, Step by Step)
Cycling a new tank means growing beneficial bacteria before adding fish. Here's the fishless cycling process step by step, and how to know when it's done.
Green Aquarium Water: Why It Happens and How to Clear an Algae Bloom
Green, pea-soup-colored water is a free-floating algae bloom caused by too much light and excess nutrients. Here's how to clear it and stop it coming back.
Fish Swimming Sideways or Upside Down? Swim Bladder Disease Explained
A fish floating, sinking, or swimming sideways usually has swim bladder disorder. Here's what causes it and how fasting and diet changes usually fix it.
Ammonia Spike in an Established Tank: Causes and Emergency Fixes
An ammonia spike in an older, established tank has different causes than new tank syndrome. Here's what disrupts an established bacteria colony, and how to fix it.
Fin Rot in Fish: How to Spot It Early and Treat It at Home
Ragged or disappearing fin edges usually mean fin rot. Here's what causes it, how to treat it, and whether fins actually grow back.
Why Are Aquarium Plant Leaves Turning Yellow?
Yellowing aquarium plant leaves usually mean a nitrogen or iron deficiency. Here's how to tell if it's normal leaf turnover or an actual deficiency, and how to fix it.
10 Beginner Fish Tank Mistakes That Kill Fish
Most beginner aquarium problems trace back to a handful of repeat mistakes. Here are the ten most common, and the specific fix for each.