Sounds like a pretty new tank, so these comments are made with that in mind....let me know if that's not corrrect.
And bear with me on these thoughts...
Real nutrient levels are dictated by the amount of food you put into the system.
The amount of food you put into the system is dictated by the type and quantity of livestock you keep in the tank.
Both of those ideas are easy to lose when designing "nutrient control".
If you plan for it to be a coral dominated system, then that should mean that they get priority over noopox, algae scrubbers, fish load, gfo and everything else.
"Dominant"
This isn't merely a saying or catch-phrase...or at least it doesn't have to be.
You
really do want corals to dominate - with a supporting bio-load of fish and other critters.
To "dominate" in this way means that the coral's carbon stream (mainly their mucus) needs to anchor as much of the food web in your reef as possible.
You
can implement this deliberately.
But
not by injecting carbon sources from human and algae-sources into the picture nor by using media/filtration to trick your test kits into saying "low nutrient" when nothing overall is really low nutrient.
Many folks short-circuit their goal of "coral dominant" in two ways:
The first is by crushing the tank with a huge bio-load of fish before anything...making it "fish dominant".
The second is by crushing it with a load of chemical media and non-coral carbon sources...making it "bacterially dominant". (Check out:
Global microbialization of coral reefs)
Coral additions to a new tank, in contrast, are usually meek and mostly an after-thought as far as tank health, if they are even considered.
That approach "can work"....but it's obviously not the direct route. (Nor is it the easy route.)
So if "coral dominant" is really a goal, those other carbon sources (human, algae, etc),
if used at all, should come later
after corals
really have been allowed to become dominant in your reef.
It may be worth stating that fish are optional to a reef. They can help or hurt the ease of care and stability factors.
"More fish" too soon makes the tank more difficult to balance...fewer fish make it easier...especially at the beginning when there's such a narrow microbial base to make use of nutrients....mostly bacterial and algae.
This narrow microbial base combined with a large influx of fish nutrients leaves a lot of room for pests and instability. (Sound like any new tank stories you've read about?)
