Good news... water parameters are more or less stable... here's my latest reading:
Sg: 1.026
Temperature: 25.5ºC - 26.5ºC
pH: 8.2 - 8.3
kH: 8 - 9
NH4: Not detectable
NO2: 0.02ppm (previously 0)
NO3: 2ppm (previously 0)
PO4: < 0.03
Everything is on track... expect NO2 to return to 0 and will tackle NO3 later