deeunit1answered grow question 4 years ago Germinated 100s of seeds and 100s of clones and I never have my fans on during the seedling stage.Look at a propagator,its covered with tiny gaps in the top with little to no air intake.Haven't had a problem with damping off,root rot for over 10yrs since using Microbes.The correct microbes will increase your roots by 200-300% and guard against bad fungi/microbes amongst many other things.Big roots=big fruits as the saying goes.