Hydroponic towers recirculate a nutrient-film solution past bare roots so plants grow without soil, limited by whichever input (nutrient, light or flow turnover) is scarcest.
growth ~ k * min(N_norm, L_norm, F_norm)
Yield += harvested_mass
Price = P0 - beta * (dYield/dt - Q0)
- Nutrient concentration — dissolved mineral strength in the recirculating film; too low starves roots, too high can shock them.
- Light intensity — LED grow-light output driving photosynthesis rate.
- Flow rate — how fast nutrient solution turns over through the channel, replenishing oxygen and nutrients at the roots.
Because all three inputs multiply together (Liebig's law of the minimum), the market price stat falls when oversupply from fast growth floods the simulated market, and rises when growth stalls.