You also need to up phosphate to a consistent level. Low phosphate can inhibit a plants ability to uptake iron.
Along with lowering light slightly and your plant choices being all low demand easy plants with no co2 I’d do this.
Fluorish comp, 4ml 2x wk
Fluorish Nit, 14ml 2x wk
Fluorish Phosphate, 24ml 2x wk but not on same day as comp.
At mid week dose test Nitrate and Phos, phos should be in .5-1ppm range, Nit in 5-10ppm range.