Yeah it’s a joke. If some situations (like growing in soilless medium with RO) then you need to add Ca & Mg. But for most growers there’s a ton of both in their feed and water and I swear 90% I see this advice it’s wrong. It’s a mystery for the ages why every single brown leaf gets a post that says “looks like a
CalMag deficiency”. It’s mind numbing.
i respectfully disagree. ever heard of soft/hard acidic/alkaline water. depending what water you have... you may have high ppm water full of cal and mag or low ppm water with little calcium and magnesium....which if you drank it all day... might actually rob your body of nutrients. Quick!!! Is your water soft? better run and check!!! you might find that you have water that is in fact not full of this so called calcium and magneseum you think it is!!!
While I will agree, most diagnosis of cal mag deficiency is rather unsubstantiated on this forum, it comes from people who have done little to no research, much like certain other people cough cough...
Let me explain... There is 100% merit behind "calcium and magneseum". Different levels of nutrients can become available/unavailable for uptake at different times. Changes to ph, temp and cation exchange/ionization zones can and do naturally effect nutrient uptake making some nutrients more available and other nutrients less available for plant absorption
Please look at the nutrient availability/PH chart below, good sir. Notice anything in particular, especially regard Cal and Mag. Interesting. It would seem Cal and Mag respond similarlyy to LOW PHs. Thus it would only make sense that they are sold together, as a deficiency/unavailability of one usually will beget the other...
Please note the data in this chart may have been updated. This is just a quick google search example.