It's Week 14 of 52 Weeks of Reefing, and this week we are going to talk UV sterilizers. We will discuss what they do and don’t do, setting realistic expectations of how they function, how to size and properly set up a sterilizer, answer some common questions, and show you the installation for the BRS160. UV sterilizers are probably one of the most hotly debated topics in the hobby with reefers firmly divided in their position of UV sterilizer’s effectiveness in closed systems like a reef aquarium. Sterilizers are designed to protect your fish against harmful waterborne pathogens like bacteria, protozoa and viruses. In a closed system like a fish tank these pathogens can spread quickly and easily wipe out the entire tank's population. So where does all the hotly contested debate come from? It’s mostly from a complete misunderstanding of the expectations of what a sterilizer is going to achieve in a reef tank. The sterilizer is only designed to reduce the chances of or slow the progression of an outbreak so you have time to research and treat your fish before they are all affected. The sterilizer is in no way even close to complete protection from an outbreak and of almost no value treating an already existing disease, algae or cyan outbreak. Once the bacteria, protozoa or virus has settled on the fish, defeated its immune system or natural resistance the sterilizer is going to do nothing to protect that fish from the progression of the disease. The UV sterilizer is simply there to reduce the chances that you ever have to deal with an issue like this and if you do give you more time to do something about it. Regardless of the side of the debate you find yourself on this is a statement that almost everyone can agree with. There is an endless amount of zoos, public aquariums, aquaculture facilities and marine wholesalers that are in the business of protecting their fish and they use UV sterilizers precisely for this reason: To protect the fish and keep them healthy. These are industries where losing animals just isn't an option and survivability equals profitability. The Emperor Aquatics brand of sterilizers in particular is popular in these in critical industries.