I'm the founding President of, "The Tank Last Club". The ideas of our founding fathers are. Research the type of livestock your planning on keeping. Be it Softies, LPS, SPS or a mixed reef, and don't forget the fish. Then precede to acquire all the equipment to make your journey a success.... The less stress you and your livestock have to endure the better???
The time you take in equipment purchases will give you a better understanding on your system and how it works. You will have to research things like skimmer size, calcium reactor size. Chiller, if needed, and the all important lighting.. This will also help in not wasting your money on future upgrades. Which can be a drain on the wallet, and mentally defeating...
I'm not saying it can't be done on a budget. although that will take more time on your behalf, to accomplish a success journey into this wonderful hobby.
In closing I started 20 years ago by purchasing my first 240 gallon
on the idea that I could fill it with water and go. Boy was I wrong, my sites were set high and the lack of equipment didn't help... I sold that system and was out of the hobby for about a year. during that time I was planning my next system. It was over a year to acquire all the equipment. I bought the tank last, wasn't going to make the same mistake again..
My current 500 gallon has been running for about 21/2 years. It to was about a year in planning, and it was just an upgrade from my 280 gallon. The system pretty much takes care of itself. Sure I do weekly water changes, and tinker around about 2-3 hours a week. But it is rock solid in water parameters, thanks to all the pre-purchased equipment...
Happy Reefing