ive been dealing with these things for over two months, it comes in waves, i think there might be silica in my water when i do water changes.
ive started to use an algacide from API thats some how safe for my corals, ill see how it works out.
i did a phosphate test and im between 0 and .05 i have a few macro in my fuge but still some green showing up in my main tank.
i also have some silica removing resin which i dont know if it helped out or not for the diatom problem.
i had some aptasia on one of my rocks, i killed the first one w/ super glue but another one popped up beside it a week later, so its currently covered under a pressed piece of epoxy which should hopefully kill it, if not the poison water the rock is soaking in will kill it, hopefully the coraline i started to grow will regrow.