Plagron Promix is a mix of the very best, carefully selected types of peat. The addition of various types of fibre results in a lightness and oxygen level found only in Plagron quality substrates. No nutrients have been added to Promix, only Plagron worm castings. The worm castings stimulate the growth of soil organisms and activate the organic fertilisers which have to be added as from the first day. This makes Promix the perfect potting soil to fertilise organically according to your own judgement and choices. The result is a 100% organic yield. Promix produces the highest yields when used with Plagron Alga Grow, Alga Bloom and the additives from Plagron.