Nitrogen Cycle Made Easy: Get Your Tank Fish-Ready!

Why the Nitrogen Cycle Matters
Think of your aquarium as a mini city. Fish make waste, leftover food breaks down, and things can get toxic fast. In nature, water dilutes it all, but in your tank, ammonia builds up quickly. Cycling your tank grows helpful bacteria that turn harmful ammonia into nitrite, then into safe nitrates, keeping your fish happy and alive. Skipping this step? Major fish casualties incoming.

Kickstart Your Cycle—Without Fish Stress
Start your nitrogen cycle by adding an ammonia source—either pure ammonia or decaying fish food. Skip putting fish in until the cycle is complete. If you want a bacteria boost, grab Nutrafin Cycle
from Pets Warehouse.

The Three Stages of Cycling Your Tank

Stage 1: Ammonia Alert!
Fish waste and rotting food break down into ammonia, which is toxic even in small amounts. Test your water every 2–3 days using a API Freshwater Master Test Kit
until ammonia levels start dropping.

Stage 2: Nitrite Time
Bacteria converts ammonia into nitrite, also toxic. Watch your nitrite levels rise and peak about 1–2 weeks into cycling, then slowly drop as bacteria populations grow. Keep testing every few days to stay on top.

Stage 3: Nitrate & Chill
Final bacteria convert nitrite to nitrate, which is mostly safe in small amounts. Keep nitrate in check with partial water changes or live plants. Your tank is fully cycled when ammonia and nitrite read zero and nitrates are below 20ppm. For water changes, treat new water with Seachem Prime 500ml
.

Quick Cycling Tips

Never rinse filter media with tap water—it kills good bacteria. Rinse in removed tank water instead.

Don’t mess with pH unless absolutely necessary; beneficial bacteria hate sudden swings.

Test your water regularly. If you’re unsure, take a sample to your local Pets Warehouse for free water testing.

Pro Tip: Patience is everything. Tropical tanks take about 5–7 weeks to fully cycle. Coldwater tanks can take even longer. Keep monitoring, keep testing, and your fish will thank you with happy fins and vibrant colours!