Iodine a must? i dot add ti and my tank is thriving, who every said that is lieing, ebcause iodine can destory your tank, you cnat measure it properly and you cant add the right ammount, why do all people add iodine, it is eveil NEVER ADD IODIN UNLESS YOU KNOW WHAT YOUR DOING!
infact dont even add it, do water changes.
chemicals - bad!