For basic fish or hardy coral keeping you do not need a substate or a sump as long as you do the water cahnges. what they they call bare bottom tanks are very popular. the rock will do the filtration you need. as long as you have a protien skimmer running. lights? well it depends on if you are wanting to keep fish or corals or both? I think my sugesstion to you would be do your home work. give a good objective look at what you will need to be sucessful. the internet is full of information. DO YOUR HOMEWORK. everyone has an opinion. this worked for me but maybe I just got lucky? I look back and wish I had done some things differant. but you cannot change the past!!!! the one thing I would tell you is do not use tap water PLEASE USE reverse osmosis deionized water. this will set you on the right path for sure.