Hands deep in water
Instead of marine buffer have you tried something a bit stronger? I use a combination of soda lye and washing soda to keep pH above 8.1. With even just washing soda the nano struggled with 8.0. And without really ramping up dosing it would try to find 7.8 or so.Well it was sorta fun but I think i've been beat at the nano tank. I've tried everything the PH is now below 7.8 and no matter what I do nothing will help. I've lost a fish and now my coal are dying. Everything looks good I even have the light at 8%.
If you have a small doser I would try getting your nano on it. Just be careful as soda lye can cause chemical burns and respiratory distress when mixing.