Perfect parameters is a trick question really. There are no perfect parameters that work for everyone, just what is perfect for your setup. Once people realize this and are not chasing numbers it is easy to keep a reef. Patience and thinking things through before jumping to conclusions, not making drastic changes or changes that were not needed effect your success more then sticking to the perfect parameters. Stability and testing are important for most people yes. But people like me that have been in the hobby a long time don't test often so testing doesn't have as large of an impact with me. But for most people it will.