Second time around, my reef is now up and running for just under a year (although it's the same exact thing that was running before except for the corals were mostly removed and a lot of the rock was given away). I don't put much time into it a day. For me, someone who doesn't do water changes, the key is to get the correct balance of organisms in your tank. I don't need to scrape often because I have lots of snails, and a lot of herbivores. I also have a large population of scavengers, and I don't feed very much (although I've been feeding more lately). My xenia grow like mad and facilitate the removal of nitrates, and I supplement with trace elements, iodine, strontium, molybdenum, magnesium, and drip kalk. It ends up taking less than 5 minutes per day, and everything is doing great. Once you achieve balance in your tank and a more or less self sustaining eco-system, then you just need to maintain it consistently. Like anything else, it will take a while to get it set up right, and then it can sustain itself. The initial set up of my reef, by the way, was back in the early 90s, so my rock and substrate have been through it all.