How often do you need to replace the nutrient bottles? Is it a new set for every grow?
3-5 are supposed to last an entire grow, but i think most people end up having to replace them during the grow, this all depends on Grobo’s recipe and nutrient dosage. i had to break into another set of 3-5 my 3rd week of flower. Depending on the water you use and if you pH it before it goes into Grobo…1 & 2 will last multiple grows.
Also if there’s no hiccups during your grow. Not all grow length is based on the actual recipe. I went through 1.5 bottles of 3, 4, 5 and almost all of bottle 2. It’s better to have more on hand just in case. My grow was 138 days… With that being said, you don’t want all that time to go to waste…