Try to avoid coming close to the plants for a while to give their roots a chance to take hold. After a couple month, they should take hold well enough for you to get near them. Also, is it the vaccume that's the problem, or do you knock them loose when re-adding water? I take my water bucket, and place it higher than the tank, then use the vaccume hose to syphon the water back in so there is less turbulance from the water, and found that helps a lot with the plants. Used to be a routine for me to clean then tank, then replant all my java ferns. Now it's just the moss that refuses to stay where I want it...