I left for the Bahamas in the middle of December for about 10 days. I had a house sitter, so I prepared a cup of food for each day - I usually feed 4 cubes of frozen, a scoop of reef roids and reef chili, and I have an auto feeder feeding pellets twice a day. Since I was going to be gone for that long, I decided to feed less to prevent any problems. I filled the cups with 3 cubes of food, and took my auto feeder offline. The entire time, my nitrates were undetectable. I'm sure there were enough nutrients in the tank that were being used before they could be detected. Colors were great, but PE was always non-existent - my palmer's blue millie looked like a blue smoothskin acro. I blamed it on the angel. I first noticed something was strange halfway into my trip. I didn't have wifi, so I really never carried my phone on me. We were on a cruise and happened to be sailing a few miles out from an island where I must have caught a cell tower briefly, and I got an Apex alert about high alk. I try to keep mine around 8.6dKh, it was now at 9.4dKh from dosing about 180ml of soda ash a day. I reduced my alk dosing by half, saved, and lost signal. A few beverages in coconuts with little umbrellas later, I had forgotten about it. The leading cause of dead acropora. Also helps forget trivial things like 100s of dollars down the drain in coral. Fast forward to the end of the week. I get home and ask how things went with the house, and head downstairs. The tank has no algae on the walls, so our house sitter must have scraped them for me - that's nice. I head over to the fridge and grab some fish food. Walk back, and that's when I see the damage; burnt tips. I test alkalinity manually, the Trident is reading high at 9.8 dKH. Hanna comes back with a reading of 10.2 dKh. I kill the doser, feed the tank, and unpack from the trip. The next day, STN shows up - and it comes hard. I don't change anything drastically - just try to wait it out and let alk lower on its own. Since I was overdue for an ICP test, I gather a sample and mail it out. Over the next few days I'd lose a few acros - TCK Pikachu, AV99 Orange Passion, WWC Yellow Tips, and an Orange Passion. My ICP test evaluation comes in and aside from a slightly low bromine levels, everything looked good. It hits me like a ton of bricks - nitrates bottomed out, calcification stopped, alk rose and boom - you have a recipe for disaster. I dosed up my nitrates with KNO3 over the course of a few days until it hit 10ppm. STN slowed and stopped, some of the burnt tips healed, and I'm starting to get polyp extension again. Frick. I've taken my skimmer offline, and have been having to dose nitrates daily to keep the levels detectable. Everything seems to be recovering nicely. I plan to start dosing nitrates daily so this won't happen again.