I agree in part with PaulB, your system is over filtered and you need to grow healthy microbial stuff. But since corals promote the microbial stuff beneficial to them I see them as essential to establishing healthy microbial stuff. However if you setup your system using without any wild or maricultured live rock or live sand to add a lot of teh microbial stuff that can't be cultured and stuck in a bottle, it will be a painful process just getting the needed microbial processes with just corals. I would be doing small weekly water changes ( <10%)
siphoning out any nuisance algae. If indeed you set up your system with just bottled bacteria or live rock that only had nitrifying bacteria added I would get some live rock from one of the Florida companies or Aquabiomics live rubble and/or live sand. You didn't list any additives but if you are adding any "carbon dosing" products designed to feed bacteria growth I would stop using them as that they can promote heterotrophic bacteria that consume oxygen (hence the often reccomended increase in water flow) or worse, promote pathogenic microbial shifts in teh microbiomes. Be patient. You need to chose a course of action and stick to it as it may take weeks to months to see significant improvements and be wary of quick fixes that show short term benefit but don't help establish long term stability.
A note on "recommended"or "ideal" parameters. We can only test for the dissolved inorganic forms left over in a system and can give an overly simpl;istic or false impression of what bing processed in a reef ecosystem. We can't test for particulate organic and dissolved orgaqnic forms of carbon, nitrogen and phosphorus. When these organic forms are considered, food webs in reef ecosystems become much more complex. Here's quotes from two reknown researchers abour nutreints and corals:
"Our crystal-clear aquaria do not come close to the nutrient loads that swirl around natural reefs. And so when we create low-nutrient water conditions, we still have to deal with the rest of a much more complex puzzle. Much like those who run their aquarium water temperature close to the thermal maximums of corals walk a narrow tight rope, I can't help but think that low-nutrient aquariums may be headed down a similar path." Charles Delbeck, Coral Nov/Dec 2010, pg 127
"Imported nutrients are usually transported form rivers; but if there are no rivers, as with reefs remote from land masses, nutirents can only come from surface ocean circulation. Often thia supply ia poor, and thus the vast ocean expanses have been reffered to as "nutrient deserts". The Indo-Pacific has many huge atolls in these supposed deserts which testify to the resiliance of reefs, but the corals themsleves may lack the lush appearance of those of more fertile waters. Many reefs have another major supply of inorganic nutrientsas, under certain conditions, surface currents moving against a reef may cause deep ocean water to be drown to the surface. This "upwelled" water is often rich in phosphorus and other essential chemicals." J. E. N. Veron, "Corals of Australia and the Indo-Pacific" pg 30. (I would note "upwelling" provides PO4 levels of up to .3 mg/l to corals.)
