Hello everyone, today I found some plants with the...

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High leliantu, Yes you are 100% right! This is a calcium dificiency. Calcium deficiencies are common when growing in coco or using soft or filtered water, but the most common reason to see a calcium deficiency is low pH at the roots. Make sure that you use pH 5.8 during watering. You need to use a Cal-Mag supplement. To supplement with extra Calcium… (it’s very rare to give a cannabis plant too much calcium, however, too much calcium can lock out other nutrients so don’t go overboard) Calcium and magnesium deficiencies often appear together in cannabis. You can solve this with some Calcium-Magnesium (Cal-Mag) supplement. After supplementing with Cal-Mag and correcting the pH, you should expect to see new healthy growth within a week. Remember, the old leaves will probably not recover, but new growth should be green and healthy. Happy Growing! 😋