I'm a fairly advanced hobbyist with a couple of decades of experience yet every time you think you have a handle on things there is more to learn. My latest setup is a 30 gallon mixed reef. The tank has been set up for 9 months now and has had its ups and downs. I've been using All for Reef and doing weekly 10% water changes with natural sea water since day one. It took me a few months to get things stable with alkalinity and calcium but seem to have found the sweet spot. Even with water changes a few months ago my nitrates crept up to 15 parts per million. I used Brightwell Aquatics export nitrate cubes in a plastic container in my sump with great success. Nitrates are now under 5 PPM but what I have noticed is my alkalinity has been increasing. Only up to 9.7 but enough for some of my sps to burn at the tips and others to clearly stress out. The question is.... Does the denitrification process add significantly to alkalinity? Should I reduce my AFReef or remove some cubes?