For the initial start up, You are probably fine with that. However, I would not continue using that much since it would probably elevate the salinity of your system.
When the bottle says use an ounce or two per gallon, that is like if you are going to spray a gallon over water over 100 square feet of your garden. So in the future extrapolate that to using an ounce or two per 100 square feet of planting space in your system.
The overall growth of creatures depends on the availability of nutrients in the environment because Nitrogen is an vital component of proteins and other cellular constituents. Nitrogen is plentiful in the earth's atmosphere in the form of N2 gas.
Aquaponics is the combination of aquaculture and hydroponics. The key component of aquaponics is nitrifying bacteria These little organisms are essential to successful aquaponic gardening because they create the nitrogen cycle that turns fish waste into plant food.