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I have some big rainbows in my tank, and the only thing I find that I need a little less of is nitrate. I still need to dose phosphate occasionally, and the fish won't help with any of the other nutrients.
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.