Guides
Twelve long-form guides on the parts of fishkeeping that decide whether a tank thrives or quietly fails: cycling the filter, holding the parameters steady, stocking without overloading it, keeping to a schedule, and spotting trouble before the fish show it. Freshwater, saltwater and reef.
Start here
Almost every first-tank failure traces back to the same three weeks. Cycle the filter before the fish arrive, learn what the numbers mean, and know what to do when they go wrong.
Getting started
What ammonia, nitrite and nitrate readings mean week by week, how to prove the cycle is finished, and why most stalled cycles are a pH problem.
Read the guide →Water chemistry
All ten parameters worth measuring, target ranges by tank type, how often to test each one, and what a bad reading is actually telling you.
Read the guide →Troubleshooting
Why fish die in a two-week-old tank, how to size the emergency water change to the reading, and the well-meant fixes that make it worse.
Read the guide →The routine
Tanks rarely fail from one bad week. They fail from drift — a schedule that slipped, a filter nobody serviced, a nitrate reading that crept up over three months.
Routine
The daily sixty-second check, the weekly slot, monthly equipment service and the quarterly jobs everyone forgets, scaled to the size of the tank.
Read the guide →Routine
How much and how often, why small and regular beats large and occasional, and what changes when the tank is saltwater rather than fresh.
Read the guide →Equipment
What you genuinely need, how to size a filter and a heater, the kit worth skipping at first, and the service intervals that prevent silent failures.
Read the guide →Stocking
Compatibility failures rarely look like a fight. They look like a fish that stops eating, hides for three weeks and dies — and the cause was decided in the shop.
Stocking
Parameters, adult size, temperament and territory — the four axes that decide whether two species can share a tank, and the classic mismatches to avoid.
Read the guide →Stocking
Why the inch-per-gallon rule fails, what actually limits stocking, realistic numbers by tank volume, and the signs a tank is already overstocked.
Read the guide →Stocking
Hardy species that tolerate a learning curve, with adult sizes and group numbers — and the popular beginner fish that are a worse idea than they look.
Read the guide →Going further
Marine chemistry is not harder than freshwater chemistry. It is less forgiving of drift, and corals react in days where fish hide a problem for weeks.
Choosing
What is genuinely the same, what is genuinely different, the honest cost and time comparison, and which to start with given your situation.
Read the guide →Reef
Why the big three move together, why an alkalinity swing burns coral tips within days, and the modern position on nitrate and phosphate.
Read the guide →Health
The symptoms worth learning, what each one usually means in freshwater and saltwater, and why quarantine is the only prevention that reliably works.
Read the guide →General guidance, not a prescription
The ranges, intervals and timings across these guides are typical, not universal. Requirements vary by species, tank size, water source, stocking level and climate, and a target that suits one animal may be wrong for another. Verify anything that affects an animal's health against your own test results.
TankSync's reference content, including its species data and AI features, is informational and is not veterinary advice. It does not diagnose or treat illness. Where an animal is unwell, consult an aquatic veterinarian.
Ten water parameters with safe ranges applied per tank, trend charts, recurring maintenance with due dates, a cycling dashboard and 857 species of care and compatibility data. Synced across your devices through iCloud, with no TankSync account to create.