I have a buddy who is going to give me his 14g biocube that is already been running for a while. My question is I have ordered mj 900, media intank insert, fishsaver insert. Do I change components out while tank is full or do I need to remove water to make upgrades. The tank is run as a fish tank which currently has two clown and one live rock. Also what testing equipment will I need to get inorder to keep everything in good running condition.