The study was performed by using a factorial experiment in a randomized complete block design with three replications at the research greenhouse, of Ilam University. The effects of acidification of the irrigation water were examined on Mg2+, Fe2+and chlorophyll content. Treatments consisted of six level acidity of irrigation water (A1: pH=4, A2: pH=4.5, A3: pH=5, A4: pH= 5.5, A5: pH=6, A6 (water) pH =7.8) and two cultivar of red and white flower geranium. The results showed that acidification of irrigation water was significantly increased leaf Mg2+, Fe2+and chlorophyll content. It is recommended that in areas with high soil pH and EC, acidity of irrigation water as much as pH=5.5 by using of substances such as nitric acid, phosphoric acid, sulfuric acid, enhance the quantity and quality of flower.