SoHum living soil and CalMag

[Johnny Bravo]

I read that when using R/O water along with LED lights that plants can develop a CalMag deficiency. I plan on using SoHum soil in 7 gallon fabric pots. In case my plants do run into a deficiency, what would be a good source of CalMag to use? I currently have a bottle of 'Fox Farms Cultivation Nation CalMag' but I don't want to use it if it's going to kill the beneficial microbes in the SoHum soil.

 

[Rasterman]

I read that when using R/O water along with LED lights that plants can develop a CalMag deficiency. I plan on using SoHum soil in 7 gallon fabric pots. In case my plants do run into a deficiency, what would be a good source of CalMag to use? I currently have a bottle of 'Fox Farms Cultivation Nation CalMag' but I don't want to use it if it's going to kill the beneficial microbes in the SoHum soil.

I have the same concern, so have been doing foliar spray only - just to be sure. Not that I actually know whether that's the right thing to do...

 

[MotaZona]

I’m trying 75% RO & 25% well water that’s in limestone this run. I believe I’m experiencing the same thing when using straight RO.