a friend of mine has a 4ft aquarium and has had it set up for almost a year. he has angels. gouramis. tiger barbs etc and plants . he told me he does weekly water changes ' 3 buckets' and has never used any water conditioner since the tank has been set up and all fish are doing well. I use stresscoat when I do my weekly changes and was wondering if anyone else just adds water to tank without treating it?