ULNS
/U-L-N-S/
Ultra-Low-Nutrient System. NO₃ < 1 ppm, PO₄ < 0.02 ppm.
An approach to reefkeeping that targets very low nutrients via heavy skimming + carbon dosing + GFO. Produces saturated SPS colors but is dinoflagellate-prone if pushed too far. Triton Method is the most popular ULNS framework.
Recommended
Affiliate linksFor dialing in low-nutrient tanks without crashing into dino territory.
Hanna Marine Phosphorus ULR Checker (HI736)Phosphorus in ppb for ULNS tanks. Multiply by 3.066 for PO₄.View on Amazon →Brightwell NeoNitro nitrate supplementAdds nitrate to ULNS tanks fighting dinos.View on Amazon →Brightwell NeoPhos phosphate supplementAdds phosphate to ULNS tanks fighting dinos.View on Amazon →
Affiliate links. As an Amazon Associate, reefcalcs earns from qualifying purchases.
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Last reviewed