Test for the basics...ammonia, nitrite, nitrate, Ph, SG
, temp, calcium, ALK
. No real need to add any suppliments as long as you do regular water changes. This will replenish any depleted trace elements and should buffer the ph
what do you like or feed your corals?
It really depneds on the corals you are keeping. Most do require special or intense lighting for energy. In a sense, they eat light. they will also eat free-floating foods in the water. It really varies from coral to coral so it s a hard question to answer.