The Disper solution you are searching for Lettuce is Alghum, at a dose of en foliar type application or 5-15 kg/ha y ciclo in fertigation type aplication, with a number of 2 applications.
Disper Alghum GS is an exclusive combination of American leonardite and Ascophyllum nodosum that enhances the hygroscopicity and aeration of soils, stimulating the plant and conferring greater resistance to stress thanks to the natural components of the algae.