If you have multiple peristaltic pumps, you can dose a multi-part solution in a defined ratio.
By default, all nutrients will dose in a 1:1 ratio. To change this, you will set dosing ratios per pump. Go to Settings > Configure Modules, then select a pump. Under "Dosing Ratio (%)" enter a number between 1 and 100. This is the percentage of "full" dosing. (Pumps without a value will pump at 100% of capacity.) At pump set at 50% will dose at half the rate of a 100% pump; a pump set at 25% will dose at 1/4 the rate of a 100% pump.
For example, if you have a three part solution and want to dose at a 2:1:1 ratio, you would set the dosing ratio for A to 100, and the ratio for B and C to 50. (B and C will both dose at half the ratio of nutrient A.)