I have determined after many years that the concept of sterile soil is a myth. I have microwaved and baked soils to try and keep them "clean" and something always shows up later: algae, U subulata, my pregnant plant, grass, Godzilla, etc. I finally gave up figuring that the soil in nature ain't sterile and the plants live fine there so my soil didn't really need to be sterile either.
And Parasuco, don't worry about being annoying, start new threads whenever you want. I promise no one is going to get angry.
Pyro