I'll try . Setting up a 30 to move bubble tip and star polyps to. I treaded with priZpro no results. Need to treat the whole tank 200gl.
Fish are all 6-5 years old no fish since then. Yes to new snails and blue legs maybe 6 months ago.
Nothing has changed just this disease but something triggered it
Diseases/parasites can enter the aquarium from almost adding any new lifeform. If the crab and snails came from a system where fish were in or where the fish were a part of the same system is a possible source of entry. Also, although many suppliers and fish stores might keep fish separate from invertebrates, there may be crossovers
vis a vis the use of nets, droplets of water, etc. Cross contamination isn't all that uncommon.
Praziquantel in PraziPro is an anthelmintic (deworming) medication. It fights flukes/worms. I don't think the fish you have are demonstrating any of the symptoms associated with flukes. There is a caution about using PraziPro: PraziPro is considered reef safe. The
glycol solvent in Prazipro is a carbon source and bacterial growth scavenges oxygen when it is dosed. So when using this medication it is
very important to add an airstone. I always recommend one airstone for every 30 gallons of aquarium water (different locations in the tank).
Medications are often not reef safe. Even if you do treat the main display tank, the nitrifying bacteria and various small lifeforms will suffer and/or die off. Not to mention the lingering medication that 'hangs around' after the treatment.
I believe after doing the freshwater dip, I'd like to know what you see/notice of the fish and in the dip water.
The fish should be treated using copper. The information is here on doing that: Download then read, the
Copper Treatment Procedure document. This treatment addresses Marine Ich as well as
Amyloodinium ocellatum (Marine Velvet) and a few other parasites. If the fish have Marine Velvet, they most likely would have died by now, since this parasite acts quickly.
A healthy diet is important. Are the fish still eating? Download then read, the
Fish Nutrition document. Help the fish by improving its immunity and ability to heal wounds by adding supplements for an ill fish to its diet as recommended in the
Fish Nutrition document. Click on that link, then download (and read) the document. Use especially Beta-1,3/1,6-D-Glucan found online, in health-food stores, and pharmacies. Directions for its use and quantity is provided in the link.
Without skin scrapes and a microscope, it is a challenge to determine what is happening. If this is a skin/surface bacterial infection spreading to the fish, then treating with a fish antibiotic would be the way forward. Treating with copper or an antibiotic must be done in a separate (hospital) tank. One of the most common surface bacterial medications is Metronidazole. The medication Metroplex contains 70% Metronidazole.
Like stated above. . .these treatments are not done in the display tank.