Get the water right.
The fish follow.
Free aquarium calculators and field-tested freshwater guides — written from a real working fishroom, not scraped from somewhere else.
Calculators built from real tanks.
Everything to get started right.
New here? Start with this guide.
Everything you need to get started — the right order to read our guides, which tools to run first, and how to avoid the 10 most common beginner mistakes.
★The Nano Cichlid Hub
Dwarf cichlids for small tanks — Apistogramma, rams, shell dwellers, and kribensis. Species selection, tank setup, and stocking for 10–40 gallon tanks.
★The 10 Gallon Tank Hub
Everything about 10 gallon tanks — what fish work, what doesn't, 5 stocking plans, and setup essentials.
01Aquarium Water Parameters Explained
pH, ammonia, nitrite, nitrate, GH, KH — what each number means and what to do when it's off.
02Choosing the Right Tank Size
Every size from 5 to 125 gallons (19–470 L) — what each suits and what fish work.
03Best Fish for a 10-Gallon Tank
Nano fish, bettas, shrimp and four complete stocking combinations that actually work.
0410 Beginner Mistakes to Avoid
The predictable, avoidable errors — and how to sidestep every one of them.
05Low-Tech Planted Tank Setup
A thriving planted aquarium with no CO₂ and no expensive kit — the Walstad method, simplified.
06Aquarium Filter Types Compared
Sponge, HOB, canister and undergravel — which filter fits your setup and budget.
That 5 cm fish becomes a 30 cm predator.
The size you see in the store tank is the smallest the fish will ever be. The "nano" label means nothing if you're looking at a juvenile. Before you impulse-buy, look up the adult size — or you'll be rehoming an Oscar in eighteen months.
Read the guide →
Written from real experience — and real mistakes.
Years of hands-on, multi-tank experience — documenting the science, the mistakes, and what actually works: an active bristlenose breeding project, low-tech planted tanks, and unheated setups that hold through extended power cuts. The photos here are all from our own tanks.
Bristlenose Pleco Breeding for Beginners
Caves, conditioning and raising fry — from a working BN project, including the albino-longfin line.
Read the guide →
The Walstad Method, Done Properly
No CO₂, no dosing — just soil, plants and a self-sustaining ecosystem that genuinely works.
Read the guide →
No-Heater Tanks: Cold-Water Species That Thrive
The freshwater fish that thrive unheated — perfect for low-energy systems and variable room temperatures, year-round.
Read the guide →Guppies: Friend or Foe?
After keeping guppies twice — the harassment, the mystery snail they killed, and why I keep them species-only.
Read the article →The Truth About Endlers
Tiny, shimmering and adorable — but mean in their own way. My Japan Blue trio, the shrimp, and what went wrong.
Read the article →Build your tank the right way.
Start with the tank size calculator — 30 seconds, and you'll know exactly what you're working with before you buy a single fish.