Beginner aquarium guides

53 guides, in the order a first tank needs them. Each one answers one question and commits to the answer.

Fish & Plants

Stocking counts, tank mates, feeding and sick fish. 19 guides.

Fish & Plants13 min
Best Food for Betta Fish: Picks by Size, With Label Data
The best food for betta fish is a betta pellet sized to its mouth. Six picks compared on label protein and pellet size, plus how many to feed a day.
Fish & Plants14 min
Best Tropical Fish Food: Picks by Where Your Fish Feed
The best tropical fish food for a community tank: a staple for the smallest mouths, a sinking food for bottom feeders, and a jar you can finish in 3 months.
Fish & Plants13 min
Ghost Shrimp Breeding: Eggs, Larvae and Which Ones Need Salt
Ghost shrimp breeding works in freshwater for most US ghost shrimp. How to spot the eggs, when they hatch, raising the larvae, and which kind needs salt.
Fish & Plants9 min
How Many Guppies in a 10 Gallon Tank? Five, All Male
How many guppies in a 10 gallon tank? Five, all male. Add females and two can drop 40 to 80 fry a month. See the breeding math and what to do instead.
Fish & Plants9 min
How Many Neon Tetras in a 10 Gallon Tank? Eight, and Why
How many neon tetras in a 10 gallon tank? Eight, kept on their own. Six is the floor and ten the ceiling. The math, plus how to add them without losses.
Fish & Plants10 min
Betta Fin Rot: Signs, Treatment, and When to Medicate
Betta fin rot usually starts with dirty or cold water. How to tell it from tail biting, the clean-water fix, when to medicate, and how fins grow back.
Fish & Plants7 min
What Fish Can Live With Goldfish? A Short, Honest List
What fish can live with goldfish? Another goldfish first, then a few cool-water fish and snails, with temperatures, sizes and the ones to avoid.
Fish & Plants4 min
Betta Lying on the Bottom of the Tank: Resting, Cold or Sick?
Bettas rest on the bottom more than most fish, and often it means nothing. How to tell a resting betta from a cold or sick one, and what to check first.
Fish & Plants5 min
Can a Betta Live With a Goldfish? No, and Here's Why
Can a betta live with a goldfish? No. Goldfish need 20 gallons and strong filtration, bettas need calm water, and their temperatures barely overlap.
Fish & Plants4 min
Dropsy in Bettas: The Pine-Cone Sign and What You Can Still Do
Dropsy in a betta shows as a swollen body with scales raised like a pine cone. What causes it, whether it spreads, early treatment, and when it is too late.
Fish & Plants8 min
How Big Do Goldfish Get? Size by Type, Age and Tank
How big do goldfish get? Fancy goldfish reach 6–8 inches, commons 8–12 or more. Size by type and age, wild records, and what really stunts growth.
Fish & Plants3 min
How Long Can a Betta Go Without Food? A Week Is Fine, Two Is Not
A healthy adult betta can go about a week without food, and survives up to two. How to plan a trip, which feeders to avoid, and why a betta stops eating.
Fish & Plants3 min
How Long Can Goldfish Go Without Food? Up to Two Weeks
A healthy adult goldfish can go a week without food easily and survives about two. How to prepare for a trip, why feeder blocks backfire, and ponds in winter.
Fish & Plants7 min
How Often to Feed Goldfish: Schedule by Age and Water Temp
How often to feed goldfish: once or twice a day, what they eat in 1-2 minutes. See how much in grams and a pond feeding chart by water temperature.
Fish & Plants4 min
Swim Bladder Disease in Bettas: Usually Food, Sometimes Not
A betta floating sideways, stuck at the top or unable to leave the bottom usually has a digestion problem, not a disease. How to tell, and the 3-day fix.
Fish & Plants2 min
Why Is My Goldfish Turning Black? Check the Ammonia First
Black patches on a goldfish are often healing ammonia burns, which means the water was bad recently. Otherwise it is a natural colour change. How to tell which.
Fish & Plants2 min
Why Is My Goldfish Turning White? Age, Light or Water
A goldfish fading to white is usually age, genetics or too little light. White spots, patches or fuzz are different. How to tell a harmless fade from a problem.
Fish & Plants4 min
How Many Fish in a 10 Gallon Tank? A Straight Answer
How many fish in a 10 gallon tank? Six to eight small schooling fish, or one betta plus a clean-up crew — and why inch-per-gallon keeps killing tanks.
Fish & Plants4 min
Pothos in an Aquarium: Safe for Fish, Risky for Shrimp
Pothos in an aquarium is safe for fish and a strong nitrate exporter — roots in the water, leaves in the air. The real risk is the pesticide on the plant.

What you'll find here

These guides follow the order you actually need them in: choosing a tank and working out what it really costs, the equipment that matters (filter, heater, light, substrate) and what you can skip, the nitrogen cycle and how to run a fishless cycle properly, then stocking (beginner-friendly fish, easy live plants) and the maintenance routine that keeps it all stable.

Every guide is written by a named human author who keeps tanks, gives you the numbers to test against rather than vague advice, and gets updated when better information turns up. Read more about our editorial standards.

Fish & Plants

Best Food for Betta Fish: Picks by Size, With Label Data

Best Tropical Fish Food: Picks by Where Your Fish Feed

Ghost Shrimp Breeding: Eggs, Larvae and Which Ones Need Salt

How Many Guppies in a 10 Gallon Tank? Five, All Male

How Many Neon Tetras in a 10 Gallon Tank? Eight, and Why

Betta Fin Rot: Signs, Treatment, and When to Medicate

What Fish Can Live With Goldfish? A Short, Honest List

Betta Lying on the Bottom of the Tank: Resting, Cold or Sick?

Can a Betta Live With a Goldfish? No, and Here's Why

Dropsy in Bettas: The Pine-Cone Sign and What You Can Still Do

How Big Do Goldfish Get? Size by Type, Age and Tank

How Long Can a Betta Go Without Food? A Week Is Fine, Two Is Not

How Long Can Goldfish Go Without Food? Up to Two Weeks

How Often to Feed Goldfish: Schedule by Age and Water Temp

Swim Bladder Disease in Bettas: Usually Food, Sometimes Not

Why Is My Goldfish Turning Black? Check the Ammonia First

Why Is My Goldfish Turning White? Age, Light or Water

How Many Fish in a 10 Gallon Tank? A Straight Answer

Pothos in an Aquarium: Safe for Fish, Risky for Shrimp

What you'll find here