I don’t mind at all I love talking about nutrients. It’s a black hole of knowledge and I think one of the most important params to a healthy reef.
I have a wonderful thread somewhere here about trying to lower rising phosphates over a long period of time. It definitely leaches in the rockwork and can take a year or two to start decreasing! Basting your rock work and dead spots is one of the best things you can do.
The thread taught me that macro algae and water changes actually barely effect PO4.
Certain foods are crazy high in PO4. Ditching reef roids , reef energy, and just feeding mysis / live phyto with heavy cleanings caused my PO4 to start dropping drastically and naturally, but it took a long time.
GFO caused my tank problems.