You are planning a reef tank, where there is little room for mistakes in design or execution since corals are not tolerant. Therefore, take your time. I know it is frustrating to see your magnificent tank sitting there, and nothing happening, but it will be great, eventually, if you take your time. Give lots of consideration to your lighting. A 210 gallon tank is pretty deep, so you are going to need intense lighting (LED banks, or metal halide) to deliver sufficient light to the bottom of the water column. As pointed out above, an effective skimmer is also important (but you won't actually need it until you are a couple of months into having stock in your tank). Also, you might want to consider exporting nutrient through macroalgae, either free floating in a sump, or by using a algae scrubber. These are either diy, or you can buy them online (not cheap, but very effective). In your plans, be sure to include a sump, and if possible, have the return pump bulkheaded rather than submerged. This will avoid heat transfer and save you the cost of buying and running a chiller. JBJ makes a good-enough auto topoff system which will save you infinite daily work making up for evaporation. You will also need 2-4 powerheads in the tank to circulate water and produce necessary wave action. Think about these items, ask questions, read and follow the threads on this site. After you decide on your hardware choices, bring them up for discussion here, and then assemble the system. Then we'll talk about sand, rock, water, salt, cycling, and eventually, stock choice. Just remember, nothing good happens quickly in saltwater tanks, so take your time to get each step right before moving on.
