Water parameters
Temperature, pH, and the ammonia–nitrite–nitrate cycle. Stable values matter more than chasing a textbook "ideal" number.
Freshwater Aquarium Reference
A stable freshwater tank is built on routine, not luck.
RiverAndWillow documents the parameters, filtration, and stocking choices that keep a planted freshwater aquarium steady through a Canadian year — from cold winter tap water to summer temperature swings.
Last updated: May 29, 2026
The three pillars
Three systems decide whether a tank stays healthy.
Most freshwater problems trace back to one of three areas. Each has its own guide, and they are easier to manage when you treat them as a connected system rather than separate chores.
Filtration
Mechanical, biological, and chemical stages. The biological stage is where most beginner tanks succeed or fail.
Plants & livestock
Choosing species that tolerate your real water, your tank size, and each other — instead of forcing incompatible combinations.
The nitrogen cycle
A new tank needs time before it needs fish.
Fish waste releases ammonia, which is toxic. Bacteria convert ammonia to nitrite (also toxic), then other bacteria convert nitrite to nitrate, which is far less harmful and removed by water changes. Establishing those bacterial colonies is called cycling, and it cannot be rushed.
Until ammonia and nitrite both read zero on a test kit, the tank is not ready for a full stocking.
Read the water parameters guideammonia (NH3) -- toxic
| Nitrosomonas bacteria
v
nitrite (NO2) -- toxic
| Nitrobacter bacteria
v
nitrate (NO3) -- low toxicity
| removed by
v
water changes
Recommended order
The setup sequence keepers tend to follow.
Plan
Test water
Cycle
Plant & stock
Maintain
1. Plan & test
Pick a tank size you can maintain, then test your local tap water for hardness and chlorine/chloramine before buying livestock.
2. Cycle
Run the filter and let bacteria establish. Add fish only once ammonia and nitrite stay at zero.
3. Maintain
Partial water changes and filter checks on a regular schedule keep nitrate low and the system stable.
Contact
Questions about a specific setup?
Send a short note about your tank — size, water source, and what you are trying to keep — and a reply will reference the relevant guide. This form runs in your browser only; nothing is transmitted to a server.
General reference inquiries: info@riverandwillow.org