It’s very thick and velvety and keeps coming back no matter how much of it I remove. It’s way down in the cracks so it’s difficult to remove it completely. I just added some reef flux today because I heard that can help so I’m keeping my fingers crossed. My nitrates are at around 5 at the moment and phosphate is around 0.04 so I’m working to lower those as well to help the situation. Thanks for your help.