Thank you! All that info is perfect. Thank you guys as well, @HotRocks @4FordFamily , great info.Here's the "All things QT" links, if you want to check some of this info out before getting started:
https://www.reef2reef.com/threads/thread-links-to-all-things-quarantine-fish-inverts.602917/
I'd say, if your plan is to treat them all together, 40g would be the minimum tank size I would use. Fallow period for brook/velvet is 6 weeks, ich is 76 days (the longest known dormant encysted strain was 72 days, plus a 4-day buffer) Snails, crabs, corals, etc can't host parasites so they can stay... just no fish.
If you want to split them up, I'd keep the wrasses together in one tank and the heavily afflicted in the other. Can split up the rest however you'd like... but wrasses don't always tolerate copper so well, so it would be better for them to ramp the copper up over 4-5 days. Obviously, the tangs and heavily-covered fish don't have have the liberty of the same ramp-up time, so that tank you would want to reach therapeutic sooner (2-3 days max).
I use cupramine (ionic copper), and have for quite some time. But, many prefer to use copper power (chelated copper) with more sensitive fish like wrasses. Whichever copper you get, you'll need a corresponding test kit. For chelated, you'll need a high-range kit like API. If you go with ionic, Seachem makes a test kit specifically for use with cupramine that works pretty well. There is also a reference test included so that you can double check that you have actually reached therapuetic. Hanna checker will do both.
Therapuetic level for chelated copper is 1.75-2.0
For ionic, it's .5
You want to keep the level as steady as possible during treatment. Dose water-change water before it goes into the tank to ensure there is no fluctuations, even momentarily. And test frequently, at least daily for the first couple of weeks. You might see the level drop a bit initially as the tank/equipment/sand for wrasses absorb some, but it should be minimal. Don't use live rock or any other porous media that can make absorption worse. Copper treatment is 30 days for a single QT, or 14 if you are able to transfer them to another clean QT for observation after. IF you separate them for the copper treatment, they can come back together for the observation period in a single QT. Don't lower the copper level prior to transfer.
I'd also dose an antibiotic (Furan-2 and/or kanaplex are fine to use with copper) in with the heavily covered fish. Metroplex is another good idea for both tanks, for the antibiotic properties and also the off-chance there is brooklynella involved here. Antibiotics should be used for at least 10 days, or as long as 14 if needed. Should do water changes as instructed, dosing copper into the new water first as mentioned above.
Ammonia test kits won't work in copper, so you'll need an Ammonia Alert Badge, and plenty of Bio-Spira or other bottled bacteria products to manage ammonia. Do NOT use Prime or other chemical ammonia reducers, they amplify copper toxicity tenfold and will kill all of your fish.
Make sure to keep the QT well aerated, power-head(s) aimed at the surface and an air-stone. Meds can deplete O2 fairly quickly, so this is important.
I'm not sure I can think of anything else off of the top of my head right now, but read through those links and send me a message or tag if you aren't sure about something and I can try to talk you through it
he was my first sw fish , he will be missed. Currently having his cadaver sit in RODI, looking for flukes..
Thanks dude! Yea this sucks, even more frustrating I didn’t add anything wet, so I can’t even blame it on a fish or even a frag
Thanks, now time to fix this before it claims another !Sorry for the loss
YeaI’m sorry for your loss as well, especially with the emotional attachment of being your first fish
Yea
Just so others can learn and stuff; I RODI soaked my clown. A few things fell off him. Are these flukes? Very sorry for the graphic nature of this pic.
Below his gills are little crumb looking things.
I checked on him at 3am and he was still moving, then at 10am I found him dead and immediately put it in RODI. He’s been in there an hour now. Makes sense about the parasites moving on.
Thanks brother, yea this really is hitting me harder than I thought it would, it’s so hard to see them go when you’ve had them a long time
I’ve never been great with death 
Losing my Sailfin ,Pac Man, after 6yrs was hard especially since I feel really guilty for neglecting tank maintenance when I started college. We actually buried him like a pet in the garden and planted tulips next to him. I still feel like a p.o.s. when I look at old pictures and he's in at least 75% of them.Thanks brother, yea this really is hitting me harder than I thought it would, it’s so hard to see them go when you’ve had them a long time
Ugh sorry to hear that. Hopefully better luck with the remaining fish!Thank you! All that info is perfect. Thank you guys as well, @HotRocks @4FordFamily , great info.
My clown passed away this morning
They’ve been holding it off for an impressive amount of time.
