for what you want to do, id say get a five pound bag of crushed coral and a five pound bag of aragonite for substrate. add ten lbs of live rock and a small filter for movement and youve got the start to a good tank. i dont use skimmers on either of my two tanks and my parameters are tight as long as feeding is kept in check and the tanks arent crowded. i change the filter cartridges twice a month and water change every other week and that works for me. might not be the same for you but shouldnt be TOO different.