[Resolved] 2 questions, first is about medium the second is about air at roots

Hello this is the first of two sets of questions that I require answered please. For this set let me start with a question regarding medium to be used. I will be starting my second grow in a few weeks or so and for this first grow I was financially restricted and had to use what I could get. For my second round I won’t have that problem so I would like to know what medium I should buy that will provide the best results for my medicine and if possible can be reused. Second question is regarding air at the root system. I have a few air pumps and a small pile of air stones, would I receive a benefit from adding these to the next round or would it just result in a higher electrical bill? Thanks for your help with this matter.