Yeah, am a definite BBA novice. 'Tis true.
But, appears like you cant get a half dozen experts on it in a room together without coming up with at least a few different answers. Those experts leave all of us novice's with a "spinning head".
But, we still come back and ask them.
So, Im putting in a little bit of each that I hear here:
To much detritus in sand- Ill change it out.
Need more nutrients in water column. Ill try adding more.
Turn down photo-period a bit. Ill do that.
Clean as much as you can off plants, substrate, hardscape- check.
The only thing that is missing is balancing of Co2. Now, my very uneducated guess is that this is my biggest problem. But, not going to go there-- so, your right--- this may just be all for naught.