i let mine sit in a 5 USG bucket with a small PH for between 30-45 min., then i will "drip" the water in the tank with airline tubing. takes about 30 minutes, and my fish seem to love me so far. its only a 20L, so i dont like to dump water in, as it may cause a "tidal wave". used to use a heater and let it sit overnight, but my heater broke unfortunately.