CalMag in Hydro Grow

[beav406]

I change water and nutes in my hydro grow every 7 days. My question, I've never used CalMag so I thought I would try it. Do I add CalMag at every water change, veg thru flower?

 

[RetiredGuy]

Is there any method you use to tell which strains need it before a deficiency shows up? I always add it because I am using RO water and I still got a few deficient upper leaves this grow.

 

[BU2B]

If your water source has minerals removed, there's a good chance that CalMag may be needed for the entire grow. I find that the kush's like their extra CalMag or they let you know about it. But, I still wait until or if the plants indicate a need for extras before I actually add them. Phenotype and strain variations keep me from adding it as a matter of course.