CalMag on Coco

if it's washed and buffered properly, it is an absolute myth you need "more" calcium or magnesium.... just not true. you need the same amount if you grow in any other soilless medium, pH will impact it,but too acidic is the concern typically. you need about 100-130ppm of Ca, depending on how hard your local tap water is. it should be added to your fertilizer every single time. you should be fertilizing every single irrigation with 10% runoff. simple as that to maintain an equilibrium. if you neglected the runoff, you could have a buildup but not enogh info given... just makes it possible with bad habits. if you continue to experience ph drift even with proper fertigation habits, then you need to consider changing your fertilizer as it is not ph-buffered. that is a needless headache that is easily avoided with a better fertiilizer brand. also, if you follow these habits it's never a guess of is it too high or too low. you canlook at the numbers of your mixed formual (ppms) and it should be obvious. The 10% runoff ensures it stays roughly around that level - likely slightly higher, but each 10% runoff resets it to the same point each time. No guessing if there is buildup in the substrate. can't happen. if you have a tox simply means you have to re-formulate with less of that particular molecule and no flushing necessary. (extreme situations require a "flush". i haven't needed to 'flush' a plant in 5 years, lol, it really is avoidable) Leafe symptom chart -- Mg is NOT Ca. they are 2 unique things with different symptoms. google image search will provide numerous examples to compare pictures to what you see. Ca would be rusty dots. mg would start with interveinal chlorosis and then get some spots as it worsens. where it starts on the plant is important for diagnosis too. the 'jorge cervantes' stamped leaf symptom chart is the one i use.