One thing i've noticed when away from the tank for 4 days is ALK consumption goes up.. I tried to simulate the reason by not touching the tank for 4 days (when home), but no conclusions. For example, Alk was 7.9 range for weeks and after 4 days away dropped to 7.2dkh. This has happened to me at least 5 times. I figured it was overfeeding when I was home but its something else.. Perhaps higher PH with no one in the house, not cleaning the glass, or that I tend to feed heavier the day before leaving. I would advice anyone leaving get there tank used to pellets on a autofeeder and increase you 2 part dosing slightly perhaps 5-10% Also, I got a cloud cam from amazon which is excellent since I leave the cabinet open so I can see the tank, lights(if there on or off), water level, ATO, Temperature, and doser, etc