Fix the water. Enjoy the fish.
Aquarium problems explained step by step, and the equipment designed for them. Research-based, beginner-friendly, no hype.
Substrate, Plants & DecorGravel, sand and plant soil, live and artificial plants, rocks, driftwood and decor that are safe in a tank.48 guidesFilters & MediaCanister, hang-on-back, sponge and internal filters by tank size, plus the media inside them.61 guidesTanks & StandsTanks and starter kits by size and fish, and stands rated to carry them.29 guidesAir, CO2 & PumpsAir pumps and stones, water and return pumps, and CO2 systems for planted tanks.42 guidesLightingLED fixtures by tank length and use: fish-only, low-tech planted, high-light planted.19 guidesSaltwater & ReefReef and marine gear: all-in-one tanks, skimmers, powerheads, salt and auto top-off.15 guidesWater Care & TestingTest kits, conditioners, bacteria starters and treatments, each tied to the water problem it addresses.24 guidesCleaning & MaintenanceVacuums, siphons, scrapers, algae tools and buckets.16 guidesFood & FeedingFish food by species and diet, and automatic feeders for holidays.9 guidesHeaters & ThermometersHeaters by tank size and control type, and thermometers to check them.15 guides
Recent guides
Air, CO2 & PumpsBest Battery Backups for Aquariums: Air Pumps and Power Stations
Tanks & StandsBest Betta Fish Tanks for 2026: 8 Kits From 2.5 to 20 Gallons
Substrate, Plants & DecorBest Aquarium Plant Fertilizers: What Each One Supplies
Food & Feeding9 Best Tropical Fish Foods: Flakes, Granules and Pellets
Food & FeedingBest Betta Fish Food: Floating Pellets, Flakes and Treats
Substrate, Plants & DecorBest Aquascaping Tools: Tweezers, Scissors, Spatulas and Kits
Useful reading from Fishkeeping
Tank Setup & CareHow to Set Up a Fish Tank: A Step-by-Step Beginner’s Guide
StockingFish for a 10-Gallon Tank: 13 Species Sources Recommend and How Many to Keep
Tank Setup & CareHow Long Can Betta Fish Go Without Food?
New in Water Lab
- How to Lower Nitrates in a Fish Tank: Water Changes, Plants and Media
- How to Lower pH in an Aquarium, Naturally or With a Product
- Liquid Test Kits vs Test Strips for Aquariums: Which Is More Accurate?
- How to Lower Nitrites in a Fish Tank, Step by Step
- How to Lower Ammonia in a Fish Tank: Steps and the Long-Term Fix