Grotek Grotek Cal-Max 10LProduct Details During periods of high temperatures and accelerated growth, plants can develop nutrient deficiencies, which are preventable. Cal Max was developed to provide the additional calcium, magnesium and iron needed to support peak production. Applied as a foliar spray, this product can help even in environments where nutrient translocation from roots to leaves is difficult or not occurring at all. Cal Max can be used to treat nutrient