I started a fishless sps experiment about 3 weeks ago(a 100 gallon rubbermaid stock tank). First I added Bio-Spira, then I added about 1ppm ammonia, some phosphate, and some organic fulvic acid(the tank doesn't have lights now). In two weeks the tank fully cycled, and I measured 25 nitrate. I started adding 0.8 grams of ammonium chloride two times a week( if all the ammonium is turned into nitrate it should add at least 7ppm of nitrate a week), and I started dosing 4ml of vodka a day. Today my Nitrate measured 10ppm. I don't have a skimmer on the tank, I don't see a lot of denitrifying bacteria growth, hopefully I can get away without using a skimmer. I believe that in a reef tank acropora get the vast majority of their nutrition from ammonium/ammonia and phosphate, and I also think they may need to have humic substances it the water. When I get the nutrient import and export where I want it, and I get the water parameters were I want them, I will add light to the tank, and I may add a test coral.