You need to explain what the 'water' is to be used for. If it's to grow plants I doubt that: NO2- is 0.06μM

Paul Milham Hi Dr., sorry I forgot to add detailed information. We are using artificial seawater dissolved from sea salt and add these two chemicals as nutrients into water for seagrass growth.

Thanks fur the clarification. Unfortunately that is outside my experience. I think you will fund that there is an internationally agreed standard for seawater. Good luck.

Composition of Hoagland solution which is commonly used for solution culture may be seen. As I remember the concentrstion of NH4NO3 is 5 mM and the concentration of KH2PO4 is1mM. I think similar composition can be tried.

The following reference may give some idea to choose nutrient concentrations in solution culture or sand culture for optimum growth of plants.

Comparison of nutrient solutions for growth of plants in sand culture. G. S. Smith, C

M. Johnston and I.

S. Cornforth. New Phytol. 94,537-548 , 1983. The public ation is available on internet.

Annangi Subba Rao Dr., thanks for your advice, will have a look.

Yuxin Liang

To calculate the amount of NH4NO3 and KH2PO4 you need to add to the artificial water solution for seagrass growth, you'll need some additional information:

1. Concentration Needed: Determine the desired concentration of NH4NO3 and KH2PO4 in the solution. This concentration will depend on the specific requirements of the seagrass and may require some research.

2.Volume of Solution: Know the volume of the artificial water solution you're preparing.

3. Molar Mass: Find the molar mass of NH4NO3 and KH2PO4. This is the mass of one mole of the substance and is used to convert between grams and moles.

Once you have this information, you can follow these steps:

1. Calculate the number of moles: Use the formula:

\( \text{moles} = \frac{\text{mass}}{\text{molar mass}} \)

2. Determine the mass: Once you have the number of moles, use the molar mass to find the mass of the reagents needed.

\( \text{mass} = \text{moles} \times \text{molar mass} \)

3. Convert to grams: Convert the mass from step 2 into grams if necessary.

Here's a basic example calculation:

Let's say you want to prepare 1 liter of artificial water solution and you want the concentration of NH4NO3 to be 0.1 moles per liter and the concentration of KH2PO4 to be 0.05 moles per liter.

1. Calculate the moles:

For NH4NO3: \(0.1 \, \text{moles/L} \times 1 \, \text{L} = 0.1 \, \text{moles}\)

For KH2PO4: \(0.05 \, \text{moles/L} \times 1 \, \text{L} = 0.05 \, \text{moles}\)

2. Find the mass:

For NH4NO3: \(0.1 \, \text{moles} \times \text{molar mass of NH4NO3}\)

For KH2PO4: \(0.05 \, \text{moles} \times \text{molar mass of KH2PO4}\)

3. Convert to grams: Convert the masses obtained in step 2 to grams.

Remember, this is a simplified example. The actual calculation may require more specific data and considerations depending on your experimental needs.