Assessment of water quality of the ex-sand mining sites in Pasir Sakti District East Lampung for tilapia (Oreochromis niloticus) culture oleh Qadar Hasani, Niken Tunjung Murti Pratiwi, Yusli Wardiatno, Hefni Effendi, Herman Yulianto, Maulid Wahid Yusuf, Rachmad Caesario, F Farlina