Background: I have had three Chromis Veridis for about 3 months now in a 5 month old 29 Gallon tank that is very stable, although a bit on the dirty side nutrient-wise. The other two are showing no signs of stress or illness. No other tank members are showing any signs of stress or illness. All tank members have gotten along very well, no signs of aggression outside of normal Chromis pecking order behavior. Corals are all healthy and showing moderate growth.
I don't have a build thread yet for any of my tanks, mostly a lurker, so here's the details for this tank.
29 Gallon STD tank
5 months old
10 lbs live-rock that came from LFS
1.5 inch avg sand bed depth
Ammonia: 0
Nitrite: 0
Nitrate: 25-30
Phosphate: 0.8-1
Alkalinity: 9-10
Ph: 8.0-8.3
Temp: 79F
Salinity: 1.025-1.026 (ATO with RODI)
Calcium: 360-390
Water appearance: very clear with extremely light floating particulates
Water Changes: 5 gal every other week, reef crystals modified for alkalinity match
Tankmates: 1x Cleaner Shrimp, 2x Emerald Crabs, 5x Mexican Turbos, 5x Nassarius, 1x Trocus, 2x large bristle worms (hitchhiked), some aptasia (not under treatment yet), some vermetid snails (not fighting them yet either), 1x small Zoa Colony, 1x small Hammer, 4x small NPS gorgonians, 2x small GSP, 1x small pulsing Xenia, plenty of pods, plenty of diatoms, plenty of algae
Feed: 3x a day-hatchery diet slow sink pellets (20 or so tiny pellets), 1x a day-1/2 tsp reefroids, 1x a week 1/4 tablet frozen mysis or marine feast
Supplements: Reef complete, Iodide, reef plus, seed
Equipment: hob, UV, skimmer, heater, smatfarm 90w, 1x 500gph power head creating a top to bottom gyre across the tank
Three days ago this Chromis initially was hiding in it's sleeping spot even after the lights came up and would not come out for the first or second feeding. When it finally came out, the whole head looked like it would not un-camouflage. It fed very lightly during the third feeding, maybe two pellets, but was swimming normally. Yesterday it came out normally but was not swimming with the other two, who kept circling back to try to bring it with them to their swimming spot in the flow. It did not eat well yesterday either, but some of the blackness on the head started to fade. Today, I fed mysis and it ate lightly again. I noticed it breathing heavy despite more dark coloration fading, but it is also now having a problem staying afloat. If it doesn't aim up, it starts to sink and has rested on the power head suction mount several times.
I am pretty sure it's not being bullied, as the other two keep trying to go over to it and get it to go to their normal swimming spot with them. The dark markings are the same on both sides, so I thought maybe injury to the color nerve, but I can't imagine from what and breathing is now labored, not improving. There are no visible sores or pests on close inspection that would lead me to believe uronema or flukes. Most of what I've been reading today has either not aligned to what I'm seeing or doesn't have any resolution other than a reported death. Does anyone have any ideas or solutions that have worked with the described symptoms?
The best pics I could get,