I started cycling my dry rock aquascape (45 pounds) for a 65 gallon proclear 90 around June 10th with sponge filter (2 large ones) and Seachem matrix substrate from my established tank along with Dr. Tim's one and only, salt water start, microbacter along with ammonium chloride dosing everyday (no live rock used). I cycled until 5th of this month when I was convinced there was no ammonia and no nitrite and nitrates spiked to 60-80 ppm. It could handle ammonia spike of 1.5 ppm in a day and nitrite to nitrate took some time. Transferred all my cycled rock to the display tank with a large bottle of biospira dosed and been adding a mysis shrimp cube everyday. Earlier my tank showed 5 ppm nitrates and now it seems to be dropping to 1 ppm. I had some diatom show up but it has stopped spreading. I would not expect denitrification to happen at this stage - is that even possible ? Is my tank ready for vinegar dosing? I have a reef breeders photon 32 on a cycle of 10 hours and still not a lot of algae. Ammonia - 0, nitrite - 0, nitrate - 1 ppm. Nitrate levels tested with nyos, salifert. 40 pounds of live sand used for a 1.5 inch sand bed). As seen in the pic, there is a maxspect gyre at 40% for flow which should somehow eliminate low flow areas for anaerobic bacteria to set in.