Yes, I did an emergency big water change, over half the tank’s running volumes.  Took out 10 gallons.  Why?
Well…turns out when I set up this stand of tanks, I set it up in front of a closet in the rental’s basement.  Didn’t think anything of blocking the closet…we’re not using it.  Well..turns out our main water shutoff is in that closet.  So when the plumber showed up today to fix some plumbing issues in the rental house, guess what he needed to turn off 😉
So..drain drain drain drain drain drain drain.  Slowly move the 2 tanks on the stand across the concrete floor just enough to open the closet and narrowly reach in to turn off the valve.  Then fill fill fill fill fill.  But I DIDN’T think to save any of the water I was draining.
I had water mixing up already for a regular full strength water change, but I used that to quickly add some water to the top QT tank which was running with only an inch or so.  Testing out Joe Lichtenbert’s observation that fish can handle rapid salinity changes in BOTH directions.
I got another bucket mixing at full strength, and decided I would use water from an existing tank to refill the Maroon’s QT tank.  So….5 gallons out of the SPS tank, mixed with 5 gallons of dechlorinated tap water and in it went.  Honestly, the fish seemed to like it, and it was the clearest I’ve seen this QT tank in a while now.  I don’t know where the salinity is, but I suspect it’s up a little bit more now, maybe 1.012 or 1.013.  I’ll have to check it later.  When I tested it last night, it was around 1.011, and I added maybe a half gallon of distilled water to bring it back to 1.010-ish.
The interesting part, and why I say the fish seemed to like the water change, is that the female seemed to perk up rather quickly and started snapping at bits of food in the water as it swirled around.  At least that’s what I think  I was seeing.  I can say with certainty that the fin rot has not progressed since last night.  Her appetite remains iffy, and she does seem at times to be blind.
Since I drained probably 2/3 of the water, I felt obligated to hit the tank with a fresh pouch of Maracyn SW.    So now I’m back on a morning dosing routine, which is not really where I wanted to be.  (It’s easier to feed all day, do a water change in the evening, and then dose after the water change.  Now, if I do a water change in the evening, I’m diluting overnight).
Anyway, that’s the 411 for this morning!