i agree on the sand numbers but my opinions differs on the live rock, i like to go with a bit less depending on the size, shape, and density of the rock, i prefer 1-1 1/2 lbs per gallon. my reasoning is that you have a plan a reef for the long term, if you fill your tank to the max with rock now, you'll have to remove some later on to make room for your corals as a lot of the things you buy will come on their own rock. you'll still end up with the same volume of rock it'll just be a bit slower. also another thing to keep in mind if you are buying your rock local, look for large unusual shapes, if you buy a lot of small rocks and pile them up like a mound of potato's, your reef will look like, well, a mound of potato's, and you'll have poor water flow because the rocks wont have as many spaces between them. as for the sand, i like the look of the dsb but i am currently contemplating going bare bottom and replacing my substrate with hdpe cutting board to protect the bottom of my tank from falling rocks. the tank i have now does not have an algae problem but tanks in the past of mine have, and since a dsb is basically a sponge that absorbs nutrients that you don't remove from the display, i figure one day the sponge will be full and I'll have algae again, so I'm thinking I'll head that off and keep my tank as a bare bottom so that i can keep it clean, and be able to have higher flow rates without worrying about a sandstorm. i do however plan to keep my dsb in the fuge for now, since its remote, if i have a problem with it, i can just take it offline and remove it relatively easily.