In a nuthshell, the FW dip + Formalin did not really seem to go over well.  The Maroon Female is under the live rock, wedged in, breathing unhappily and rapidly.  Frankly though, I’ve seen MUCH WORSE LOOKING fish (see my posts about the Saddleback…of course, it did die within hours later).
What I’ve seen develop over the past few hours is slime coat and what looks to me like Velvet (Amyloodinium).  I’ve seen it before, many times over, as I found Amphiprion allardi particularly susceptible to it.   I know we had Brooklynella early on, then there were the Spots of Cryptocaryon, and now this.  Sure, I’m not 100% sure it is, but seriously…I dip the fish with Formalin and FW, and within 2 hours I have a nice dusting of tiny white spots on the fish?  What else could I be seeing?
Well, I’m making plans to abandon their tank potentially.  Can’t risk a Cupramine + Formalin interaction.  I took a fallow larval tank down, filled it about 50% with water from my Onyx Perc’s reef, 50% new tapwater.  It tested out around 1.014 (my percentages aren’t exact).  I’m letting it just sit there.  Depending on how the female Maroon looks in the morning (if she is even still alive) I may follow through with my earlier outlined plans and treat her with Cupramine.  Honestly, this is somewhat ridiculous to be dealing with still.
My plans for the Lighting Maroon?  I have 3 options.  #1.  Leave him in the 20 gallon QT tank since he’s doing OK there despite the Female’s ongoing troubles.  #2.  Ignore that there is another clearly sick fish in the tank, and treat him as if he’s been through a short QT and come out OK.  That means #3a – placing him in a net breeder in my SPS tank with a RBTA (Red Bubble Tip Anemone) or relocating our spawning pair of Black Ocellaris and giving the Lightning Maroon a dedicated 6 gallon reef with a massive RBTA and a bunch of mushrooms.  Both tanks are very solid.  Both have good and bad things associated with them.
Frankly, I’m frustrated, because the 20 L was solid, had been broken in for months and was going to be an ideal home for the pair.  I’ve ended up ravaging it with Hyposalinity and Formalin, and even after all that I’m stuck with sick fish?  If I have to abandon this tank and leave it fallow, I’m technically without a good dedicated home for a Maroon pair at the moment.  That’s a setback.  “GRR”