If by Flourish you mean Flourish Comprehensive, for all practical purposes that is providing the same thing as Trace. you dont need both.
Even though Flourish Comp lists macros among the ingredients (N,P,K) the amounts are negligible, virtually zero.
Therefore, what is lacking in your fert regime is nitrogen and phosphorous.
PO4:0.25
NO3: 10
Assuming your test kit is accurate, which is doubtful unless you've calibrated it, P seems the most likely candidate, 1 or 2 ppm would be more like it.
Personally I would ditch the trace and begin adding both N and P. Flourish sells them separately. Following the directions should be fine for a sparsely planted low tech aquarium.