Yesterday, I was testing my tank and my nitrates are off the chart. I went to get water and had my LFS test my water. I was sure my test kit must be off. No its high.\nAmmonia 0\nNitrites 0\nNitrates 160\npH 8.0\nI have changed 40 gallons of water about 4 hours ago.\nPossible causes:\nRedid the aquascape.\nCan't find my serpent star in sump. \nPossible overfeeding. I have cut my feeding way back.\n\nHow long should it take to fix this. My coral and fish are doing fine. I am waiting for a order of snails that I am putting on hold until I get this under control. \nThanks for any help. I am very frustrated. \n\nI have a skimmer in my sump but it is down until Monday because my husband broke the venturi piece and we ordered it overnight.