Quote Originally Posted by oldmac
hy-dro-pon-ics = soiless agriculture; the raising of plants in nutrient mineral solutions without EARTH around the roots.

Pro-Mix used in a container and feed via the nutrient solution IS hydroponics.
Whether you hand water, set up an automated top feed (drip system) or place the containers in a grow tray (sometimes called a flood table) and bottom feed (ebb & flow) to reuse nutrients....it's all hydroponics.

Suggested PH by the mfg. is 5.9, but check and see what your nutrient mfg suggests. Dutch Master recomends 6.0 for Pro-Mix. (not a big difference)

BTW Pro-Mix is one of the few growing mediums that do not require cal/mag to be added even if using RO water. It contains dolomite lime that breaks down to calcium and magnesium, one less thing for commercial greenhouse growers to add to thier RO water.

OM
Hydroponics - Greek for Water Works. Water does the work, water contains everything, the medium is 100% neutral.

Real hydroponics systems do not allow the main root structure to embed itself into a medium, roots are always given direct access to the nutrient solution instead of having to absorb it from a medium that the roots are embedded into.

Soilless mixtures hold and retain the water and oxygen, their purpose is to REPLACE SOIL and provide a place for roots to hold onto and absorb nutrition.

True hydroponics, you have no medium like that. You have at the most an initial seed starting plug and the roots just dangle away in the nute solution.

Video - TinyPic - Free Image Hosting, Photo Sharing & Video Hosting - this is a true hydroponics system. Note the distinct lack of pro-mix or anything besides rockwool.

Even the grass seed itself doesn't require a substrate.