The goal of delivering therapeutic proteins in plant cells, free of cold chain and expensive purification processes has been elusive for several decades. Recently, Angiotensin Converting Enzyme 2 (ACE2) expressed in lettuce chloroplasts for delivery via chewing gum (Daniell et al., 2022a,b) to prevent infection and transmission of severe acute respiratory syndrome coronavirus (SARS-CoV-2) was approved by the FDA for a Phase I/II clinical trial (IND 154897, NCT05433181, IRB 851459). Further product development, leading to a Phase III clinical trial in preparation for commercial product launch, requires large-scale biomass production under optimal growth conditions, for maximal yield of the target protein drug. Although there are many reports on optimization of lighting, nutrients and spacing to grow lettuce under hydroponic conditions, they focus on biomass accumulation and metabolite levels, except in one report on a vaccine antigen (Lin et al., 2013; Okamura et al., 2014). Biomass and target protein yield are dramatically lower in lettuce plants grown under hydroponic conditions when compared with the greenhouse (Daniell et al., 2020), but there are no reports on the combined optimization of lighting, nutrients and spacing to improve biomass and protein yields in hydroponically grown lettuce plants. Therefore, this study addresses this urgent need in molecular farming.