Dosing Calculator
This calculator helps you make a fertiliser solution that is
used to dose your tank by calculating the ppm (mg/l) value for a
given amount of solution added.
For a more comprehensive set of calculators consider
AquariumCalculators.com. 
How To Use 

1. Enter your tank volume and select either
Litres, UK Gallons or US Gallons. 
2. Select the nutrient you wish to use and
from the chemical it is obtained. 
3. Enter the amount of the chemical that is
to be added to the solution and also if you are using Grams,
Teaspoons or Tablespoons. This may require a bit of trial and
error to achieve the desired ppm figure. Remember that only so
much of a chemical can be added to a given amount of water  see
table below for the amounts. 
4. Enter the amount of water that is going to
be used for the fertiliser solution. 
5. Enter how much solution you wish to add to
the tank in each dose. Some people like to add small amounts at
a time like 2ml whilst others like to add large amounts like
50ml. The choice is yours. 
6. Click the 'Calculate' button to display
the ppm value. This is the amount that the selected nutrient
will raise your tank level by. 

nb. The calculator can also be used if you dose dry
chemicals by putting a value of 1 in both the 'Amount of water
to mix with' and 'Each ml of solution..' fields. 
What ppm Values Do I Need 

What amount of nutrient you wish to add depends on your dosing
schedule but if dosing Estimative Index then here is a general
guide: 
8ppm of Nitrate which is added 3x a week 
2ppm of Phosphate which is added 3x a week 
Notes 

Teaspoon quantities 
I have calculated the amount of each chemical by weighing the
amount using a standard teaspoon (5ml) which is available from
most kitchen stores. Depending on where you obtain your
chemicals from you may get slightly different weights. I get all
mine from The Nutrient Company. Here are the weights I
have used for each chemical using one teaspoon:
Potassium Nitrate 
6.0g 
Potassium Phosphate 
6.6g 
Potassium Sulphate 
5.1g 
Magnesium Sulphate heptahydrate 
5.1g 
Calcium Sulphate dihydrate 
4.1g 
Calcium Chloride anhydrous 
3.5g 
(nb.The tablespoon amount is calculated by multiplying the
teaspoon amount by 3) 

Solubility's In Water 
There are limits on how much of a salt can be dissolved in
water. As this limit is reached it becomes increasingly
difficult to dissolve more. If you are experiencing difficulties
in dissolving any of the salts then try doubling the amount of
water it is dissolved in. Below are the maximum solubility's of
the various chemicals used in the calculator.
Potassium Nitrate 
36g per 100ml 
Potassium Phosphate 
22g per 100ml 
Potassium Sulphate 
11.1g per 100ml 
Magnesium Sulphate heptahydrate 
25.5g per 100ml 
Calcium Sulphate dihydrate 
0.24g per 100ml 
Calcium Chloride anhydrous 
74g per 100ml 


This page was last updated by webmaster
 27th August 2015