Hi all, new member seeking some guidance. I've set up a 150 litre new tank from scratch and I'm 10 days into a fish-less cycle. Some basic info: 150 litre tank 1,150 l/per hr canister filter 7.2 pH 6 dH GH 4 dH KH No plants yet Cycle temp 30 dC Ammonia source - Waterlife (SeAquariums) Bio-Mature My questions is - how often should I be adding the ammonia? The reason I ask is that by following the instructions to achieve 5 mg/l, by adding he correct amount once a day, after a couple of days, the ammonia level was dropping back to zero within a a few hours. This went on a few days but the nitrites failed to increase above 0.1 mg/l. I am assuming this is due to high capacity filtration I have? To combat this, I'm having to add ammonia to the tank at least twice a day to stop the ammonia reaching zero, which after a few days, I'm finally seeing the nitrites starting to rise, which I guess is good news. Nitrates are still similar to tap water, so I know I'm still only at the second stage. Am I correct to keep the ammonia at or close to 5 mg/l until after the nitrite spike has occurred? It just seems like I'm adding an awful lot of ammonia just to keep the levels up as directed. If I get the Ammonia to 5 mg/l and don't add any more, it will be zero within 6 hours and the nitrite then fails to rise. Could do with some pointers as to bet practice to ensure a successful cycle. Is my large filtration the reason for having to add so much ammonia to keep levels up? Thanks in advance.