A couple things. First, just for clarification, and I apologize if you already know this. But I think it’s worth noting that there are actually 2 different kinds of carbon in reefing. The first is GAC (granular activated carbon). It is the black stuff that looks like charcoal. It is used to absorb impurities in your tank, like heavy metals (think copper). The second is referred to carbon dosing, and includes things like biopellets, and vodka. This is organic carbon. This kind is meant to increase nitrifying bacterial populations in your tank. As it grows and multiplies, it absorbs N and P. Then your skimmer removes the excess bacterial colonies from your water and the cycle repeats as you continue to add organic carbon. This is very effective and can strip nutrients from your water quickly. I use a biopellet reactor in my tank, and many would argue I run my nutrients too low, but it works for me.I do carbon dose. I was using a reactor. I tried using that reactor with PhosGaur, but could not get low enough. I use phosphate-e now. I have been putting carbon in a mesh bag, high flow area in my sump. Basically following Randy Holmes advice on carbon : ) I have a 200 gallon tank. I throw away half my carbon each time I change it out. And then add back in 1 cup... ish... every 2 weeks.
As far as your chemistry is concerned, you look like you have that under control, for the most part. Your main values seem like they are stable enough that they shouldn’t cause you issues. I went through your build thread again and didn’t see any mention about how you cycled your tank. Did you do all dry base rock with bottled bacteria to culture your cycle? I ask because I think an often overlooked parameter in reefing is biodiversity, both macro and micro biodiversity. Macro includes things like sponges, pods, tunicates, worms (yes, bristleworms as well as micro tube worms), snails, micro stars, etc... these are more “measurable” because you can generally see them. You want tube worms and sponges growing In your sump, pods in your refugium, and small snails and stars crawling on your rocks.
The second one is less measurable, but I feel is even more important. Your bacterial levels and diversity in types is critical for a stable reef. The way to increase these types of things is by using real live rock, like the stuff aquacultured in the Gulf of Mexico. Think Tampa Bay Saltwater or KP Aquatics. This will bring in more life and diversity than you can even imagine. Yes, I would quarantine the rock, to try to limit bad pests from getting in, things like gorilla crabs and fire worms. The next best thing would be to add live mud and / or live sand. And this means the real stuff not the crap you get at Petco. Actual mud from the ocean, and actual sand from the ocean. Think places like Indo Pacific Sea Farms, or Florida Pets. If you are patient, you can actually measure your microbiome. A place called Aquabiomics can do bacterial DNA analysis. If you want to see an example of what Aquabiomics can do, check out my build thread.
Now, if you did start with live rock, then I am at a total loss. Perhaps you might still benefit from adding some live diversity, but it would seem that your initial additions would have handled that. So for sake of discussion, let us know how you cycled your tank. Sorry if you mentioned that already and I missed it.