# I want to increase the NO3 concentration in a 40 Liters tank using Ca(NO3)2.4H2O. The concentration of the CaNO3 solution is 500g/L. How much solution do I need to add increase the concentration by 2ppm? Thanks for helping out!

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How much calcium would be added at the same time?

How much calcium would be added at the same time?

##### 1 Answer

#### Answer:

You must add 0.3 mL of the calcium nitrate solution. This will include 25 mg of calcium.

#### Explanation:

Let's express the concentration of 2 ppm as grams per litre.

For 40 L of water, you will need

The molar mass of

Of this, 124.01 g comes from the nitrate ions.

Hence, to get 0.08 g of nitrate, you will have to use

The required volume of concentrated salt solution is

There are 40.078 g of

∴ The mass of calcium added is