Hello Ray! I can full well understand your frustration as you muddle your way through with your figuratively speaking "instructions manual" if you will, which a term in my household is claimed as "just another man's opinion." As your knowledge base and experience expands, thus the narrowing of room for common errors will take place. Just stick with the basics and some common sense. Water quality testing is a mainstay as it will reveal the basis of tank health just as labs reveals normalicies in human blood test. When you see something rearing it's ugly head, head it off at the pass. Take corrective action before it takes hold and fully manifest itself. It is good that you personally know someone who knows your current system and status and is a good steward of marine resources. But it is also your responsibility to follow up on his information in regards to your little piece of paradise also.
Lol, so every now and then means 6 months eh? Don't take it to heart. Our little piece of the marine world is growing, maturing and adapting to their current environment as best they can. They will always have to be tweeked now and then. Mechanical items break down and slowly lose their efficiency, the aquascaping soon becomes overcrowded or loses it's appeal. There's always something to keep the hobbiest entertained, challenged and planning for the future. We always have to take 5 steps forward and two steps back as we slowly make some progress. Such is the way of the world.
When I had mentioned changing some of the water flow or current in the tank, I was referring to powerheads or some other devise that you are using. I have 2 #3 Koralia power heads in my large
DT, which I switch up all the time to change things up and to keep my tank clean and help the
skimmer do it's job. I also like to turn them on when I introduce nutrients into the tank to get it mixed well and then cut them off for feeding time.
Have your readings across the board stabalized and has the algae growth stopped spreading?