I'm simply going to elaborate on Guys points, because these are excellent starting places:
Guy":7p6o6t3u said:
1 - Plan out your reef before purchasing anything.
2 - Don't skimp on lighting, skimmer nor water circulation. Please rethink your skimmer and lighting

3 - Purchase a RO/DI water filter.
Plan in advance as much as possible, yes.
Start with how much money you have, and break it down into increments. Allotting a certain amount for a GOOD skimmer (avoid Prizm and SeaClones), a good pump for your sump, RO/DI system, and lighting.
Power compacts, metal halides or a combo of both. I have seen FAR too many people skimp on lighting at the beginning, then they are unable to figure out why they can't keep this coral alive, or that coral alive...the guy at the LFS said they could!! They usually end up buying a complete new lighting system after just six monthes :!: Plan for a canopy that will let heat escape, either open-backed, or built in fans.
Trust us when we tell you that buying good quality equipment will make reefkeeping a MUCH more enjoyable experience down the line. Do not skimp on these items. For example, the RO/DI system will help you get through the worst of the beginner-setup algae phases, it's really a worthwhile investment. Algae problems cause almost as many people to give up on the hobby as just about anything else. Leading cause would be fish-death. Pricey mistakes...so buy a quarantine tank!!
If you think you cannot afford decent equipment, save up until you can!
Keep in mind that expenditures are ongoing...reefs cost money to maintain, not just to set up.
For a sump, get your tank drilled, figure out the costs for that, plus all the plumbing required. Draw a diagram of how you wish to set up your plumbing, figure out what parts you will need, name them all, how many feet of tubing, etc, then go shopping. Be prepared to go back to the store to get the parts you didn't buy the first time

Buy a few feet extra tubing.
Set your system up DRY first, do not glue anything until you have measured, fit, measured, re-fit, taken apart, re-fit...you get the picture :mrgreen: And buy the right glue for the pieces you are using: PVC, ABS, or both, etc. You can buy most of your plumbing supplies at Home Depot, pool stores, etc. Don't skimp here, either. Make sure you have ball valves on both sides of your pump so you can change it out if necessary. Try to make sure your finished design will give you easy access and the ability to change as much as possible should something go wrong. In other words, make sure it can be taken apart again if something leaks, or if you wish to re-arrange it for some reason. Some areas will require permanence, of course. Life ain't always a bowl of cherries.. :lol: And remember, gaskets go on the water side 8O
Think this way: If something screws up, can I fix it easily?
Can I remove my protein skimmer to clean it? Can I get the skimmer cup out without breaking an elbow? Can I access all areas of the sump in case a fish ends up living in it? Do I have room for a fuge? Is my sump a bit higher than the floor, in case I need to syphon out crud?? Can I put carbon, filterfloss, phosguard, Chemi Pure, or whatever, in there easily? Do I have enough baffles? Too many baffles? Is my brain about to explode??
Guy":7p6o6t3u said:
4 - Search for pictures of tanks that appeal to you and correspond to your plan in advice #1. Do what they do

5 - Ask questions about
EVERYTHING. Gather the answers from experienced reef keepers and do what makes the most sense to you, not what is easiest nor what you wanted to hear.
6 - Nobody in the hobby knows everything but most experienced hobbiests have areas of expertise. Ask them.
The amount of live rock depends on your tank-scaping. Be choosy about the live rock you buy, pick out interesting shapes and take the time to arrange them nicely in your tank. You have to look at this tank everyday, it might as well be arranged prettily.
Do not overstock, or add animals too quickly. But some good test kits, keep a journal of your test results, and learn how to dose calcium and alkalinity. Top up your evaporated water twice a week, or as needed.
Most importantly, be patient. Rome wasn't built in a day
Keep asking questions, and be prepared for honest, blunt answers.