If I were to vote it would be based on MY system , there are no details on your system. If your temperatures are maintained and you keep shit half assed clean then def a sterile res , but if you can't control temps then beneficial bacteria and fungi may be best for you. one method will work for some where it won't for others, trying to maintain a sterile res while having temperatures way too high will probably be more work/cost than the bacteria and fungi. I was recently told to use a very weak solution of bleach so I tried a little experiment with a small amount in veg, I noticed a slight slime of some kind and didn't like it, so I added some bleach. top leaves turned a bit bright for a few days but after that they were fine (they're my current Un-VO grow, see thread). I don't use bleach anymore just because I don't like the idea of it but I do use h2o2, the amount needed to keep a truly sterile res gets costly.