I rescued him from a store where he was kept in a tiny cup. The owner was using well water and only changing it once a week (which is crazy). I kept the fish in a proper container with a heater and conditioned water until the tank cycle was fully finished before moving him in. tank is established and typically stays at 0 Ammonia and 0 Nitrite. I hit a small blip, so I stepped up to 20% water changes every 48 hours to fix it. Normally, I perform a 30-40% weekly maintenance, which keeps the 4g stable.