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.46 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.28 guidesAir, CO2 & PumpsAir pumps and stones, water and return pumps, and CO2 systems for planted tanks.41 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.23 guidesCleaning & MaintenanceVacuums, siphons, scrapers, algae tools and buckets.15 guidesFood & FeedingFish food by species and diet, and automatic feeders for holidays.6 guidesHeaters & ThermometersHeaters by tank size and control type, and thermometers to check them.15 guides
Recent guides
Water Care & TestingBest RO/DI Systems for Aquariums, Reef and Freshwater
Air, CO2 & PumpsBest Aquarium Air Pumps: 8 Picks Compared on Output, Noise and Tank Size
Heaters & ThermometersBest Aquarium Heaters of 2026: Picks by Tank Size and How to Choose One
Filters & MediaBest Fish Tank Filters in 2026: Hang-On-Back, Canister and Sponge Picks by Tank Size
Water Care & TestingBest Water for a Fish Tank: Tap, RO or Distilled, and What It Needs
Water Care & TestingBest Beneficial Bacteria for Aquariums: 9 Starters and What Two Independent Tests Found
Useful reading from Fishkeeping
Equipment ExplainedFluval or Aqueon Filter? Canisters and HOBs Compared, Plus Eheim
Equipment ExplainedWhat Order Should Aquarium Filter Media Go In?
Tank Setup & CareHow to Layer Substrate in a Planted Tank: Steps and Depths