you should always take your bioload into account when dosing, regardless of what's in there. a heavily-stocked tank will need less ferts than an empty tank. you should be doing tests to see what the levels are and adjust your dosing accordingly.
50gal planted - yoyo loaches, BNs, odessa barbs, giant danios
33gal planted - praecox rainbows, gold ram, bolivian rams, sparkling gouramis, licorice gouramis, lots of shrimp
2 x 5gal planted - bettas