Two weeks ago I did a 50% water change to my 20 gallon long tank. I have only 3 goldfish and a lot of Anubias a two java fern. Did the water changed cuz my nitrates was in between 40 to 60 most of the time for like a month. Feed my fish once a day and weekly 15% water changes, and didn't solve it.. Now I'm two weeks after I did the 50% water change and my water still milky cloudy. Any advice for this? Thanks