No, I don't see it as a problem, because the technology is there now such that we can handle that waste. Waste is money as well. There are different streams we can use: fertilizers, composting, and constructed wetlands.
Now, that 75,000 square feet or two acres did not include the hydroponic section or constructive wetland. The constructive wetland would be another half acre. But all that water would go back to ground, so we don't need sewage treatment plants or landfill facilities to take the waste. The feces can be composted and used as garden fertilizers or in silviculture. The guts, the offal, can be rendered down for pet foods and for mink food. There is also money in waste. The CO2 from the fish can be sequestered into the hydroponics--algae growth.
And we can control all this. This is the nice thing about it. With net pens, you can't control it.