The other way to run a reef tank (No Quarantine) I was asked by my friend Humblefish to start a thread on my practices of running a tank with no quarantine, hospital tanks, medications, dipping or almost anything else. It is "not" just to take a fish from a store and drop it in your reef because that fish will probably die. You may not see many spots on fish in a store because just about all stores use medications in their tanks to suppress the parasites. They have to because they get new fish all the time from all over the world and they can't change all the water and sterilize their tanks in between shipments. But all fish are infected in a store and even in the sea. They swim in a soup of parasites, viruses and bacteria, some good, some not so good. In the sea those pathogens are kept in check by each other as viruses prey on parasites and bacteria and other forces such as things exuded from corals and tend to keep everything in check. Of course they all prey on fish. But fish have been around almost as long as those things and they evolved long ago to live in harmony with all of them. Fish eat parasites with every meal and those parasites are processed in the fishes kidney among other places and that causes the fish to exude antiparisitic and antibacterial properties in their slime. They constantly do this and it keeps parasites and bacteria from killing the fish even though some parasites will get through to sample some fish flesh. Anyway, that is the basis for my method that I slowly learned starting in about 1973 when I had to keep fish in copper continuously as we all did. (20 pennies to the gallon) Our tanks were not reefs, we fed flakes, changed the water to much and took out the rocks and dead corals to bleach them whenever they turned green which was almost weekly. The fish were always stressed and it was hard to keep even damsels. Then I started feeding things other than flakes, things like frozen clams, pieces of fish and live blackworms. In 7 weeks my blue devils spawned and kept spawning for 7 years. Spawning damsels is no great Whop but in those days few people could keep them alive for a few weeks. I gradually learned that bacteria and parasites would not kill my fish as long as I didn't medicate them. It was backward thinking but remember there was no internet and I didn't even know anyone with a salt tank so I was on my own. When I added a fish it normally would get spots and sometimes die, but most of the time the spots receded and the fish was fine and didn't get sick when I added a new fish. That was how I learned my method which is not really a method but a lack of a method. With my method you can not quarantine because that short circuits the process. I actually want parasites and bacteria as that is what the fish was swimming with in the sea a week before. I just put the fish in my tank and normally the fish starts eating right away and is fine. About half the time the fish will show a few spots but they are very few and disappear in a day or two. Yes they finished their life cycle on that fish and dropped off to infect something else, but they can't because those fish are constantly exposed to parasites so they are immune. The things I do “not” do is quarantine. I do not ever feed dry foods such as flakes or pellets as those foods are sterile. I do not suck every bit of detritus out of my tank I do however always feed something with live bacteria in it such as frozen foods. I feed whole foods with guts such as clams, mysis, mussels and I use LRS foods which is a commercial food which I consider the best. But I still want to give the fish something that I know has living bacteria in it. I try to feed a few times a week some live worms but sometimes I can’t. Where I live now I can’t get them but I do raise live whiteworms which live in dirt. I bought a few of them years ago and that batch is still living and reproducing. I like the worms because of the living bacteria in their guts and the dirt they are living in. Some people that have immune tanks never use live worms so they may not be necessary, but I use them when I can. These things need not be fed every day, but at least occasionally. But all foods should have bacteria in it and if you feed nothing but commercial food, I am not sure how much living bacteria is in that because you don’t know how old it is or what temperature it was stored at. If you have access to a salt water beach, collect a little mud and sprinkle it around the tank. That is for bacterial diversity. If you can’t get that, you can use garden soil with no pesticides or fertilizer. (I did not invent that, it was “Robert Straughn” The Father of salt water fish keeping.) The idea is that I want parasites living in the tank along with the fish. They will keep reproducing and trying to infect fish but they will fail. I know the argument that there is much more water in the sea than in a tank and the parasites are more numerous. But that is of no consequence because the fishes immune system will get as strong as it needs to be to repel parasites and the more parasites there are, the stronger the immune system. If you quarantine fish, there will be nothing for the fish to become immune to and any slight infection will crash the tank. Fish are not delicate creatures that need coddling and they almost never get sick. They have a fantastic immune system as long as we don’t try to short circuit it. I can’t remember the last time I lost a fish to disease but it was probably in the 80s. Virtually all of my fish only die of old age or jumping out. I do lose fish due to my stupidity like if I buy something that I can’t properly feed like shrimpfish, twin spot gobies, orange spotted filefish etc. My tank is not set up for those fish and I should not buy them. But everything else, with no exception live long enough for me to get tired of them and I give them away or they die of old age. I do not like clownfish but one day about 27 years ago I bought a baby of what I thought was a red hawkfish. It turned out to be a Fireclown and I still have it. She also spawns a few times a week as all my paired fish do as all healthy fish carry eggs all the time. If you have a tank full of quarantined fish, I am not sure how you could get those fish immune because that quarantining may have destroyed the immune system of those fish. It would be a long process because the fish would have to be infected, and then cured for them to become immune and you may lose some fish. It would be much easier to start an immune tank from the start. Remember, if you see some parasites, think of that as a good thing and not something that you need to dip or treat. Yes, you may lost some fish in the beginning but your fish will become immune to just about everything and you will never need medications or disease forums. Many fish die in quarantine or right after so that is also not a panacea. I did not mention parameters because IMO they are not that important for fish health. Corals, yes, but not fish. My nitrates were 160 for years and I never had a fish die and they continued to spawn. This is my method which has worked well for decades and I never lose fish to disease which is something I think we all strive for.