The hydrated form can be prepared by decomposing precipitated and "aged" gallium hydroxide at 500 °C.
ðə haɪdɹˈeɪɾᵻd fˈɔːɹm kæn biː pɹɪpˈɛɹd baɪ dˌiːkəmpˈoʊzɪŋ pɹɪsˈɪpᵻtˌeɪɾᵻd ænd "ˈeɪdʒd" ɡˈæliəm haɪdɹˈɑːksaɪd æt fˈaɪvhˈʌndɹɪd dᵻɡɹˈiːz sˈiː.