I'd add this 2x a week and then change 5 gallon of water weekly:
KNO3: 1/8th teaspoon
KH2PO4: a smidge, about the size of a BB shot from a BB gun or a dry rice grain.
GH booster: about 1/8-1/4 teaspoon
Traces(CMS+B), I'd add 4 teaspoons to 500mls or hot tap water, and then dose about 5 mls 2-3x a week.
the rest is CO2/lighting adjustments.