Fig. 4. Solution F and complexing agent effects on nutrient solution dissolved organic carbon (DOC) over time in Study 1. HA, humic acid; HEDTA, N-hydroxyethylenthylenediaminetriacetic acid. Least significant difference (LSD_0.05) was used to compare treatment means. With increasing solution F, more HA remained in solution, likely due to a decrease in HA–Ca flocculation. Carbon in the HEDTA treatment came from the chelate.