In this paper we have developed a unique approach to providing the elements required for crop production in a steady-state condition, which is essential for Space habitats. The approach takes into consideration human elemental requirements and crop requirements for healthy growth and develops a method for the calculation of the rates of nutrient uptake for the different elements for different crops. The uptake rates can be used to calculate the rate of nutrient supply required in the hydroponic solution. This approach ensures that crops produced will not have excessive levels of elements that may be harmful to humans. It also provides an opportunity to optimize the processes of crop production and waste processing through highly controlled feed rates. Known relative growth rates (RGR) and nutrition concentration, and the kinetic properties (Maximal rate of uptake -νmax and Michaelis-Menten constant- Km) of the uptake carriers for different elements in the different BIO-Plex crops can be used and extended to include optimization of elemental use and processing in Space habitats.