I started my tank 1.5 years ago with dry rock. Somewhere in the middle of that period I decided to add more dry rock to it. The addition took my nutrients to zero which resulted in gha. While it’s not completely covered there is enough of it where my CUC can’t overcome it. My plan was just to keep dosing po4 and nitrates along with heavy feeding of meaty food. I was planning on continuing this route until the coralline algae covered everything. About a week ago my skimmer motor got plugged and I didn’t have time to get to it right away. I decided to leave the skimmer off for that whole week. The thing that I started to notice is the GHA started to recede. I would have not thought of turning off the skimmer before to fight the GHA. So just wanted throw this out as another thing to consider in your fight for a presentable tank.