Nutrient solution change during plant grow phase

[GpsFrontier]

Hello loths,
Generally speaking you should completely change your nutrient solution every one to three weeks. However there always variables to every situation. Things like the total water volume, how many plants you have in the system, how big they are, what type of plants they are, temperature and humidity etc. all play a part in how fast the plants deplete the nutrients in the nutrient solution. The chart showing how to mix the nutrients is just suggesting how to mix them for a balanced nutrient solution, each time you change them during that stage of growth.