NAN,
You bring up a point I am constantly reminding people about, & one that seems to ALWAYS be forgotten & overlooked.
Jerry Addington & You indeed hit the nail on the head!
Experienced growers here have learned, (often the hard way) ... that what works for one person may not work for others! Watching people here repeatedly getting into an argument/discussion about what is "right" (or possible) & what is not, gets a bit annoying, as there are many growers here who's minds are closed, or at least too "full" of what they already 'know"!
Oh, I think I need to go back to the greenhouse for a while again!
Before I go however, JB:
In my experience, the planting mix (or not a mix) that you use to grow your plants in, will need to be renewed every few years. Unless it is inorganic (like sand or rock) it will decay or change in some way. Indeed, as was mentioned, I also take my "used" peat or mixes and use it for other plants or in the garden, as it works great for them at that point!
Re-doing your planting mix will in fact give them new growth (a kick in the butt so to speak) & is also good for your soul!
I have found that having a form of drainage (I usually create a more "controlled method" than just poking holes in the bottom of my bog/container) ... as I have found that by allowing the water to sit & get stagnant allows anaerobic organisms to grow & eventually create a Witch's brew that will become a stinky soup; that is not good for your plants.
Besides the planting materials, by having a method of renewing or exchanging the water (thru drainage, water movement, recirculating, etc) or oxygenating the water to prevent stagnation, the planting mix will stay fresher, longer! (Perhaps try doing a search here on TF to find any possible info about different methods people are using. I am not sure what is available, but assume you may find something that could help if needed.)
Okay, I better go! I can see that I too still need more fresh air (or water) & time away with my plants.
Take care all & good luck with the plants!