A model is proposed for the simulation of nutrient solution flow in a Nutrient Film Technique (NFT) system, and uptake by plants. The system is consisted of a channel with a thin layer of a porous material. The nutrient solution would be applied via dripping emitters, uniformly spaced along the channel, and drain to a reservoir. The solution would then be compensated for water and nutrients' losses, and re-pumped to the irrigation system. The model was tested against N and K uptake by growing lettuce (Lactuca sativa L.) plants. Uptake of the major nutrients and the effects of salinity buildup were simulated and discussed.