В зависимости от выращиваемой культуры, марки минваты, климатических и световых условий и вообще технологии выращивания.   http://mobi.grodan.com/news/crop+technical+news     Aligning energy and root zone management strategies for sustainable tomato cultivation 3/5 Aligning energy and root zone management strategies for sustainable tomato cultivation 2/5 We only feed our plants when they really need it Aligning energy and root zone management strategies for sustainable tomato cultivation