You're fine. Here's what I think and links to the research. (Sorry in advance for the data bomb.) To add to your data overload, nitrates and phosphates are only dissolved inorganic forms. There's also particualte and dissolved organic forms we can't test for. So while there's solid research to keep PO4 above .03 as ppointed out above it's possible depending on the food webs in a system coral might be able to get enough phosphorus from particulate and dissolved organic forms, And to add to the complexity, if there's enough particulate and dissolved organic phosphorus it's possible coral's might be the source of increasing PO4 levels.
This system was at .4 mg/l PO4 when this video was taken. Nitrates were negligable.
I don't see any reason to keep PO4 lower than the .03 mg/l threshold level identified by Southampton University in England. Since they determined it by looking at phosphorus deficiency in corals maintained in aquaria for up to around a decade seems like a definitive lower number until we can quantify particulate and dissloved organic P used by corals. Upwelling can expose to corals to .3 mg/l so that seems like a fine number also. And at the higher end the sexually reproduced corals at the Steinhart Aquarium are being grown out with .9 mg/l PO4 and 50 mg/l Nitrate (Rich Ross is part of the research team in case anyone was wondering).
Here's more links:
An Experimental Mesocosm for Longterm Studies of Reef Corals
Phosphate Deficiency:
Nutrient enrichment can increase the susceptibility of reef corals to bleaching:
Ultrastructural Biomarkers in Symbiotic Algae Reflect the Availability of Dissolved Inorganic Nutrients and Particulate Food to the Reef Coral Holobiont:
Phosphate deficiency promotes coral bleaching and is reflected by the ultrastructure of symbiotic dinoflagellates
Effects of phosphate on growth and skeletal density in the scleractinian coral Acropora muricata: A controlled experimental approach
High phosphate uptake requirements of the scleractinian coral Stylophora pistillata
Phosphorus metabolism of reef organisms with algal symbionts
Sponge symbionts and the marine P cycle
Phosphorus sequestration in the form of polyphosphate by microbial symbionts in marine sponges
Fig 4 from "Phosphorus metabolism of reef organisms with algal symbionts"
This system was at .4 mg/l PO4 when this video was taken. Nitrates were negligable.
I don't see any reason to keep PO4 lower than the .03 mg/l threshold level identified by Southampton University in England. Since they determined it by looking at phosphorus deficiency in corals maintained in aquaria for up to around a decade seems like a definitive lower number until we can quantify particulate and dissloved organic P used by corals. Upwelling can expose to corals to .3 mg/l so that seems like a fine number also. And at the higher end the sexually reproduced corals at the Steinhart Aquarium are being grown out with .9 mg/l PO4 and 50 mg/l Nitrate (Rich Ross is part of the research team in case anyone was wondering).
Here's more links:
An experimental mesocosm for long-term studies of reef corals | Journal of the Marine Biological Association of the United Kingdom | Cambridge Core
An experimental mesocosm for long-term studies of reef corals - Volume 92 Issue 4
www.cambridge.org
Phosphate Deficiency:
Nutrient enrichment can increase the susceptibility of reef corals to bleaching:
Nutrient enrichment can increase the susceptibility of reef corals to bleaching - Nature Climate Change
Increased dissolved inorganic nitrogen (DIN) concentrations in sea water have been linked to a reduction of the temperature threshold at which corals bleach, however, the mechanism underlying this change is not known. This phenomenon is now explained in terms of increased phosphatase activities...
www.nature.com
Ultrastructural Biomarkers in Symbiotic Algae Reflect the Availability of Dissolved Inorganic Nutrients and Particulate Food to the Reef Coral Holobiont:
Ultrastructural Biomarkers in Symbiotic Algae Reflect the Availability of Dissolved Inorganic Nutrients and Particulate Food to the Reef Coral Holobiont
Reef building corals associated with symbiotic algae (zooxanthellae) can access environmental nutrients from different sources, most significantly via the uptake of dissolved inorganic nutrients by the algal symbiont and heterotrophic feeding of the coral host. Climate change is expected to...
www.frontiersin.org
Phosphate deficiency promotes coral bleaching and is reflected by the ultrastructure of symbiotic dinoflagellates
Phosphate deficiency promotes coral bleaching and is reflected by the ultrastructure of symbiotic dinoflagellates
Enrichment of reef environments with dissolved inorganic nutrients is considered a major threat to the survival of corals living in symbiosis with din…
www.sciencedirect.com
Effects of phosphate on growth and skeletal density in the scleractinian coral Acropora muricata: A controlled experimental approach
Effects of phosphate on growth and skeletal density in the scleractinian coral Acropora muricata: A controlled experimental approach
Phosphate contamination can negatively affect corals, modifying growth rates, skeletal density, reproduction, mortality, and zooxanthellae. We determi…
www.sciencedirect.com
High phosphate uptake requirements of the scleractinian coral Stylophora pistillata
High phosphate uptake requirements of the scleractinian coral Stylophora pistillata
SUMMARYSeveral untested aspects of the regulation of inorganic nutrient uptake were examined using nutrient depletion experiments with the symbiotic coral Stylophora pistillata. The total inhibition of phosphate uptake in artificial seawater lacking sodium indicates the involvement of a...
jeb.biologists.org
Phosphorus metabolism of reef organisms with algal symbionts
2657円まるいち 博多辛子明太子(無着色) 「博多の華」 (ギフト用) 180g Z6572海産物イクラ,タラコ,魚卵 Qoo10] 「博 まるいち 博多辛子明太子(無着色) | therichross.com
2657円まるいち 博多辛子明太子(無着色) 「博多の華」 (ギフト用) 180g Z6572海産物イクラ,タラコ,魚卵 Qoo10] 「博 まるいち 博多辛子明太子(無着色) | therichross.com
therichross.com
Sponge symbionts and the marine P cycle
Sponge symbionts and the marine P cycle
Marine sponges are ubiquitous colonizers of shallow, clear-water environments in the oceans (1, 2). Sponges have emerged as significant mediators of biogeochemical fluxes in coastal zones by virtue of respiring organic matter and facilitating both the consumption and release of nutrients (3, 4)...
www.pnas.org
Phosphorus sequestration in the form of polyphosphate by microbial symbionts in marine sponges
Phosphorus sequestration in the form of polyphosphate by microbial symbionts in marine sponges
Coral reefs are highly productive ecosystems that raise a conundrum called “Darwin’s paradox”: How can high production flourish in low-nutrient conditions? We show here that in three abundant Caribbean sponges, the granules that have been commonly observed in sponge tissue for decades are...
www.pnas.org
Fig 4 from "Phosphorus metabolism of reef organisms with algal symbionts"