It's impossible task to achieve since can not eradicate all the bacteria unless fish are dired out. Even q/t wont help since bacteria will be there too. Single drop of water can harbor miliions of pathogenic bactria. It matter of controlling it by keeping tank in prime condition thus healthy fish. Healthy fish can fight off certain bacterial infections. You can use
UV Sterilizer/
ozone system in q/t to minimize the number of bacteria but still it is not 100%.
Another thing, just about two decades of keeping Reef, never heard of Reef totally crashing due to bacterial infection although possible. W/ different organism/speciesof corals, each more prone to specific infection, i find it very unlikely. But I was not there. I am just speaking theoretically impossible unless some toxic material to corals somehow creeped into water causing tissue deterioration which will be followed by bacterial infections. Only time that I heard of reef tank crashed overnight was when one hobbyist bought this home made
chiller from someone who used metallic tubing (copper tubing) just to save few hundred bucks. Could not find the person who sold it and it turned out to be a staff in one of
LFS and disappered after selling. Amount of corals lost in his well established 90 G, could have bought few new brand name Chillers. All the
LR were goner since contaminated w/ heavy metal. My buddy was crying over this matter and I told him to kick himself in the B... and this be a learning lesson. Just want to share some info about S/w keeping. My motto in life, not just in hobby, is "You get what you paid for".
Similar Aquarium Fish Forum Threads 
