Thank you both!
I have increased my ferts regimen as you have suggested (basically doubled the amount I was adding of the Tropica specialized nutrition - 10ml per week now).
I have tested my GH (Sera test kit) and it is at 5dGH right now. Although I use tap water I am considering using very little amounts of seachem equilibrium to raise it to 7dGH when I water change. Is that advisable?
I have also increased my CO2 to achieve the 30ppm in the drop checker.
I will keep observing the AR mini for two more weeks to see if anything changes.
In the mean time if anyone has any other comments I am all ears!