Grodan Pargro Quick Drain is an alternative to the traditional potting container. Grodan also manufactures these blocks to have a tremendous capacity for absorbing nutrient solution while retaining plenty of oxygen for rapid plant growth. BLOCK MEASURES 6" x 6" x 6" Same quality, Same value-priced, Half sized cases. Driest value-priced rockwool on the market. Plain brown case sizes. Better quality and drainage than other value-priced rockwool. Resting saturation measurements taken from QD slabs vs. Neptune slabs. Pargro QD was 10% drier than Neptune slabs. Pargro Neptune has been discontinued.