Cycling Strategies
How to cycle a fish tank
Every new aquarium must go through the nitrogen cycle before it is safe for fish. Beneficial bacteria have to colonise your filter — a process that takes 1–6 weeks depending on your approach. Choose the strategy that fits your situation.
Bacterial Starter Products: Cycle Your Tank in 1–3 Weeks
🟢Use a bottled beneficial bacteria product to seed your aquarium filter and cut cycling time to 1–3 weeks.
Fishless Cycling: The Easiest Way to Start a New Aquarium
🟢The most beginner-friendly cycling method — grow beneficial bacteria before adding any fish, using ammonia as the sole nitrogen source.
Dark Start: Cycle a Planted Tank Without the Algae
🟡A plants-first approach that prevents algae by keeping lights off for 3–4 weeks while plants establish roots and bacteria colonise the filter.
Seeding from Established Media: Cycle a Tank in Days
🟡Borrow live beneficial bacteria from a healthy established tank to jump-start your cycle in 1–2 weeks instead of 4–6.
Fish-In Cycling: How to Cycle a Tank With Fish Already Present
🔴A guide to cycling an aquarium when fish are already in it — requires daily water testing and prompt action to protect your livestock from ammonia and nitrite spikes.