“This novel study highlights the possibility of improving the efficiency of N utilization in lettuce by applying foliar selenium in combination with an aquaponics system.”

https://www.researchgate.net/publication/357396301_Effects_of_Selenium_on_the_Chlorophylls_Gas_Exchange_Antioxidant_Activity_and_Amino_Acid_Composition_of_Lettuce_Grown_under_an_Aquaponics_Systemhttps://www.hortidaily.com/article/9387426/effects-of-selenium-on-aquaponics-lettuce/