For serious FA, 100lbs per acre is not out of the question. Depending on just how far south you are, in cold weather (winter) they may become sluggish enough they are easy targets for LMB-if present-and can be somewhat controlled in that manner.
Mozambique would be my choice if in a borderline area of survival for Blue tilapia because the Mozambique die at a higher temp.
Back to FA.. I have a customer that has a ground fed pond that has super high nutrient levels, first step is working to remove all growth-floating mats-manually. With an excess of these nutrients you are going to need to apply several methods for control. Killing it with chemical never really gets rid of it, just starts the cycle over-quicker. Killing it, waiting a week to 10 days, then applying Alum sulphate will lock up most of the dissolved nutrients and keep it from being useable to fire again, but a constant inflow of nutrients creates it's own set of issues, and proper experience applying Alum is mandatory for safety reasons with know-how on what and how much of what to use as a buffer.
It's going to be a very active management plan to implement but is probably going to be needed to get-and stay-on top of it.