I feel like My acros are not doing as good as they should be. I have had a Cherry Boom that will not polyp extend. Had the thing for while now. I know my nitrates are very low, could that be it? My phosphates are at .04 I get good PE from other corals and not so much on others. My ICP test showed high in Tin I ordered a second test I hope I brought that down, inspected my powerheads along with other items to make sure I'm not leeching tin from the aquarium. I'm going with ATi test this time which gives me Nitrates reading along with my RODI. Also I know my potassium is low along with very low Iodine. Been trying to increase both of those. I also had few swings in Temp from the summer months, noting crazy, I do have that more in check these days. I will keep you guys updated and any advice would be very appreciated. Thank You