gauging from your gallery pics you do not have an over abundant amount of corals-so the water changes should be enough of a replacement with the iodide/iodine. NSW is about 0.06mg/l--I think?? I prefer to keep mine at 0.08 to 0.10 mg/l which requires 2-3 drops per day of Lugols in my 55, but I have alot of polyps. If you start to add then test. good luck