ULNS Nitro is a complex inorganic nitrogen source designed to promote natural phosphorus uptake and nutrient control in ultra low nutrient systems which are nitrate limited. It provides an important nutrient source for nutrient assimilation and biological balance in the aquarium. It is recommended for use by advanced hobbyists.

Bleaching or coral tissue degradation may occur in ULNS systems where adequate nutrient content is not maintained. ULNS systems depend on bacterial management of phosphate in a balanced carbon and nitrogen environment which allows rapid uptake of excess dissolved organic compounds. The conversion to bacterial biomass allows protein skimming to export unwanted nutrients that would otherwise build up in the system. This recycling of nutrients requires that all necessary nutrients, i.e. nitrogen, phosphorus, and carbon be present in concert.