ok semi, or not its hydro... spin it for there sales.
Its the easiest medium for a newbie or expert..IMO But with that said, you can rarely ever dial in a grow perfectly with just one grow of any strain, but keeping in certain parameters will always produce a good grow. Know your PH in and OUT the bottom.
It does seem that growing in Promix HB you need cal/mag... if your going the chem route or organic, so if your product is not supplementing for that, then grab some and use it, and know what to look for in deficiencies. Cal/mag deffecnceies are the easy to spot and correct.