Largest Quarantined Saltwater Fish Facility. All fish go through a minimum 30 Day Quarantine. We carry Captive Bred & Wild Livestock. Angelfish, Anthias, Basslets, Butterflyfish, Clownfish, Filefish, Gobies, Rabbitfish & Foxface, Mandarins, Triggerfish, Tangs, Wrasses, Corals & Invertebrates...
Strictly pseaking it's impossible for anyone to guaranty a fish is completely parasite free. Quarantining certainly can significantly reduce the risk of "ich" bing present and fish can be treated for intestinal parasites but there's still parasites like brooklinella and uronema that potentially can be on fish and internal parasites we can do nothing about.
any coral vendors that are considered fish parasite free that, within reason eliminate all potential parasites with their own quarantine process, knowing that it’s not 100 percent possible, however take the precautions to mitigate and pests through the course of a fishless, or otherwise process, which have been shown to eliminate common parasites (but not all) such as ich, velvet, etc., with the expectation that not 100 percent elimination is possible, however due to the processes used by said vendor, it is reasonable to believe that said vendor quarantine process did totally or substantially eliminate said parasites in the thoroughness of their own procedure, understanding that although procedure may be 99.9 percent effective, it is unreasonable to believe that a 100 percent elimination of said pests is not possible due to the multiple factors and variables may be involved within an unquantifiable amount of individual cases, but May be seen in the totality of the most common results based off situations where no errors, mistakes, or contamination have been made.
Jason fox, top shelf aquatics, and wwc are some of the best quarantined pest free systems ive purchased from. They all have pretty stict qt procedures.
Honestly if you're super concerned, I'd set up a frag tank without fish. I don't know off-hand any coral farms that QT coral for 70+ days before putting them into a larger system or selling them. If there is one, it would be a fish-first vendor like TSM Aquatics.