Fishkeeping, properly explained.
Step-by-step guides, species profiles and water-chemistry tools — from cycling your first tank to breeding.
Explore The Aqua Guide — each figure links to the section it counts
Guides, Tools and Community for Every Fishkeeper
Text Guides
110+ step-by-step guides on cycling, chemistry and disease
Species Dictionary
Care profiles for 214 fish and plants
Water Chemistry
pH, hardness, salinity and the nitrogen cycle explained
Video Guides
Tutorials on setup, care and aquascaping
Forum
Ask questions and share your tank
Live Chat
Live chat rooms for aquarium hobbyists
Blog
Tank builds, articles and fishkeeping stories
Aquarium Calculators and Planning Tools
Plan and build your tank
Size the tank, substrate, hardscape and sump before you buy.
Tank Volume Calculator
Calculate your tank capacity
Substrate Calculator
Calculate required substrate amount
Hardscape Displacer
Calculate rock & wood volume
Golden Ratio Overlay
Aquascaping composition tool
Sump Designer
Size & lay out a flood-safe sump
Plumbing Blueprint
Drill holes, drains & return lines
Glass Thickness Calculator
Glass each pane needs to hold
Tank Weight Calculator
Filled weight and floor load
Equipment and running costs
Heating, lighting and CO2 — and what it all costs to run.
Heater Wattage Guide
Find the right heater for your tank
Light Intensity (PAR)
Estimate lighting strength
CO2 Bubble Counter
Calculate CO2 injection rate
Energy Cost Estimator
Calculate running costs
Setup Budget Planner
Shopping list sized for your tank
Water quality and maintenance
Keep parameters in range and your dosing right.
Water Parameters
Check ideal ranges for species
Water Change Calculator
Nitrate-based water change guide
Dosing Calculator
Calculate fertilizer dosing
CO2 pH/KH Calculator
Estimate CO2 from pH and KH
Cycling Tracker
Log a new tank's nitrogen cycle
Aquarium Unit Converter
Gallons, °F, ppm, flow & doses
Reef and marine chemistry
Mix saltwater, read salinity and keep alkalinity, calcium and magnesium steady.
Salinity Converter
SG, ppt and conductivity
Reef Salt Mix Calculator
Salt needed for a target salinity
Reef Dosing Calculator
Alkalinity, calcium & magnesium doses
Choosing and caring for fish
Stocking levels, tank mates, names and feeding.
Bioload Calculator
Calculate stocking level by biomass
Compatibility Matrix
Check fish compatibility
Fish Name Converter
Common to Scientific names
Feeding Schedule
Plan your feeding routine
Acclimation Timer
Settle new fish in step by step
Fish health
Work out what is wrong, then treat it safely.
Diagnostic Wizard
Diagnose fish, plant & coral problems
Medication Dosager
Safe dosing calculator
Latest Guides and Community Discussions
Latest Text Guides
Newest 6 guides
Popular Videos
Most watched
Latest Community Posts
Newest 6 discussions
Why Aquarists Use The Aqua Guide
Written by hobbyists
Every guide is written and reviewed by working aquarists, not scraped copy.
Calculators grounded in real bioload
Stocking and dosing tools built on actual species data, not rules of thumb.
A moderated community
Real answers from other fishkeepers, not an unmoderated forum free-for-all.