For a lot of knowledge in a very fun to learn way read the TOTM articles. Notice how they hold thier parameters rock solid and what they test for. I have learned a lot and gotten great inspiration. You don't need all the equipment right away or all the supplements but you will need, as stated above , to test the big 3,Calcium Alk Magnesium, and maintain them with water changes or dosing or another method.Also try and get a water top off system to stabilize salinity. Oh, and so you don't repeat my mistake, get a heater WITH a controller, they're cheap.