So where do I start? I have never seen products that bring down alkalinityPh Buffer also effects alkalinity which is already high .
ph naturally fluctuates from day to night .
As c02 levels inside increase ( typically at night when doors are closed and everyone is home ) ph will decrease .
No light inducing photosynthesis also causes ph to drop .
to offset this fluctuation you can 1) run a air line from outside or leave a window cracked to allow fresh air .
Run a refuge and light on opposite schedule
But .. I will say I believe The main contributor to the issues is water quality , high alkalinity along with low nutrients .