Nitrogen is one of the main three macro nutrients (nitrogen, phosphorus, potassium: NPK) required by plants and can often become the limiting factor to growth in a flourishing system. Flourish Nitrogen™ is a concentrated (15,000 mg/L) blend of nitrogen sources. It provides nitrogen in both the nitrate form and the plant–preferred ammonium form. However, no free ammonia is released because the ammonium in Flourish Nitrogen™ is complexed and unavailable until utilized by the plants. Ammonium becomes available after conversion of urea (carbamide). Flourish Nitrogen™ also provides nitrate for those plants that can readily utilize nitrate as well. For maximum benefit, use with Flourish Phosphorus™ and Flourish Potassium™. Flourish Nitrogen™ is safe for invertebrates such as shrimp.

Directions from the manufacturer: 

Beginner

Use 2.5 mL (half a cap) for each 160 L (40 US gallons) twice a week or as needed in response to signs of nitrogen deficiency (e.g. stunted growth, chlorosis). For smaller doses, please note that each cap thread is approximately 1 mL.

Expert

The beginner dose raises nitrogen by the same degree that 1 mg/L nitrate would. This dose is sufficient to provide approximately 4 g of growth (dry) or about 20 g (hydrated) over a 1 month period (assuming all other necessary nutrients are provided). For increased growth use proportionately more.

To target a specific nitrogen increase, dose according to the following formula: 0.25vn=m, where v= volume of tank in gallons, n=desired nitrogen increase (if using a “nitrate equivalent” value for “n” then use a factor of 0.05 instead of 0.25 in the formula) and m=volume of product to use in mL. For example to raise 20 gallons by 0.20 mg/L nitrogen you would use: 0.25*20*0.20=1 mL.

Because one-half of the nitrogen in Flourish Nitrogen™ is from nitrate you can get a reasonable estimate of nitrogen levels by doubling a nitrate reading.