Quote Originally Posted by faceto27
What is considered a soiless medium?
Hydroclay, rockwool, foam, sponge, coconut coir, perlite, air, hmmmm.......

Like Weedhound, I don't know anything about pro mix first-hand, but google is a man's best friend. It is indeed soil-less, composed of peat moss, vermiculite, and perlite. Peat moss is indeed on the acidic side as far as mediums go, and will continue to turn more so.

I found a website describing Pro Mix BX (but I don't know what type you have). It sounds a little ridiculous to me, considering they equate their "pH stabilizing agents" (which sounds like balogna) maintaining a constant pH to not needing an EC meter. How does pH have anything to do with how strong your nutrient solution is?

I would recommend another media, something truly inert if that's what you want. If not, try out a soil mix.

The website said this:

"The solution is Pro-Mix BX (or Pro-Mix HP).

Promix is a planting medium (often called soil-less-mix), which on the surface looks and feels just like any garden variety potting soil but is made up of only 3 basic elements; peat moss, vermiculate and perlite. This type of mix is sometimes referred to as the triple-mix.

Promix also contains agents to stabilize the PH levels (measure of acidity) at 5.5 to 5.7 thus eliminating the problem of adjusting PH levels of the water which is crucial to indoor growing.

In other words, so long as you use Promix you do not have to understand anything about PH .. or EC or PPM. In fact all you need to know is that when the plants go dry, you need to add some food to the bucket of cold tap water and feed your plants. Fairly easy I think"