Hi all, 21 litre (about 5 gallons) cold water tank (sitting around 19-22degrees Celsius) Set up for 7 weeks, with 4x white cloud mountain minnows (had 6 but 2 died within the first two weeks (possibly from ammonia poisoning?) Feeding the fish only what they can eat within about a minute, 2x daily. 0.5ppm ammonia (constant for 7 weeks) One small spike in nitrites (after feeding block while on holiday for a week) No change in nitrates from 0 Been doing weekly water change of about 50% every week Adding Stability everyday (about ¼ of cap, as advised by pet shop) Adding Prime with every water change (to the tap water not tank directly) Have used a gravel siphon to remove ‘stuff’ -> no change in parameters. Why is ammonia still present, with no change, and why is the nitrite and nitrate level not changing? It appears the tank is not cycling? Any help or ideas/tips would be much appreciated, we are confused about what we are doing wrong Thanks!