Very nice tank Paintman. Looks like there is some experience there that could be worth listening to.
We have strayed from the topic, apologies to the OP.
My experience says manual removal to get as much of the mass out of the tank as possible , think in terms of nutrient export. Bulk up on a diversified CUC. Check you parameters, but don’t sweat the exact numbers, just get them in the middle ground and give them a nudge if they wander to far. This is true for N and P too, you want more than none and less than a lot. Slow changes, steer clear of quick fixes like chemicals, you can’t expect the tank to be stable if you keep doing different things to it. And patience, your tank is still relatively young and finding its balance.
And I will say again, check out the Ross video, lots of great info.