Brownnish patches on Yellow-eyed tang

[speckled trout]

Anybody got an idea what's causing these brownnish patches. They look fairly smooth when viewed from the side.

This fish won't sit still for a second and these were the best pics I could get in over an hour of trying. I took over 60 blurry pics! He would dive back into the rocks as soon as he detected my presence. I wasn't even moving and he'd know I was there.

By the way, I had previously treated this fish in a hospital tank for ich with cupramine. The ich went away 6 weeks ago and the fish hadn't shown any other problems, so I placed him in this tank by himself. I'm glad I didn't put him in my display tank.

 

[leebca]

Pretty good photos, considering the Kole Tang is a fast mover and rarely holds still. I'm unsure of the true color of the spots because the photo lighting can be misleading. You say they are brown. Might they be red or reddish more than brown?

I have some questions that might help us with a diagnosis, if you don't mind answering them:

What kind of system do you have (tank volume, dimensions, bio-filtration method, the equipment you use, any carbon or other chemical filtration, kind of substrate, etc.).
You say the fish is alone now. What was in that tank before? How long ago? Any inverts in the tank now?
Foods you use and feeding schedules.
Do you use any vitamins? Fat additives? Any elemental or other additives to the water? Please list all.
Chemistries ââ"šÂ¬Ã¢â‚¬Å“ please give actual numbers (Ammonia, Nitrite, Nitrate, Phosphate, Silica, Ca, Alk., and any others you have)
Water parameters ââ"šÂ¬Ã¢â‚¬Å“ please give actual numbers (pH and your pH range, salinity or sp. gr. & range, temperature range)
Do you see any of the following in your system: hair algae; micro algae;cyanobacteria growths; dinoflagallate (zooxanthellae) growths; brown algae; diatom growth; slimes; colored patches on rock or substrate; etc.?
Is the water crystal clear?

:rollface:

 

[speckled trout]

Hello,

This tank still contains an engineer gobie who has been living in the tank for 2 years. I almost removed him prior to placing the tang in the tank, but my little girl begged me not to take him out. Notice the egg crate at the bottom of the tank! I had originally had the tank set up with a plenum and sugar fine sand, but this didn't work with the gobie who was constantly "undermining" my best efforts.

I have a few soft corals, glove polyps, and a tree coral that are currently in the tank as well.

The tang's spots are somewhat reddish brown, but appear more brown than red.

Tank
1. 42 g hexagon
2. no plenum, just an eggcrate to keep the rocks from tumbling when the gobie dug in the sand
3. angel and clowns were removed approx. 6 months ago.
4. filtration- Mag 350 canister filter with ceramic media added and carbon
5. filtration - Power filter with an iron based phosphate remover. I previously had a battle with hair algae. There isn't much left, just a few tufts here and there.
6. Inverts - the coral listed above and a few hermits, snails, and a couple of very small crabs.
7. Foods - Ocean Nutrition's Brine Shrimp Plus and Formula Two. I also occassionally add Formula Two frozen and Cyclopeeze. I haven't been feeding the Cyclopeeze to the tang, it was for the gobie who loved it.
8. Feeding Schedule - usually once or twice a day in the morning and evening.
9. Water Chemistry - The only ones I've measured in this tank are the following Nitrates - 20 ppm
Ph - usually 8.1 to 8.3
salinity - always around 35 ppt
temperature -usually around 72-74
I haven't really monitored this tank's chemistry very much. The previous residents included several clowns, flame angel as well as the gobie. The clowns and angel were removed about 6 months ago and have been residing in my larger display tank. They haven't shown any signs of illness or infection. They look great and feed well.
10. Other - There is some hair algae, but not a lot. Some reddish to brownnish discoloration appears on the glass. The newly introduced tang loves this stuff. It doesn't grow as readily on the rocks. The sand has never supported this because the gobie has kept it clean. I'm assuming that the brownnish discoloration on the glass is diatoms, but I'm not sure.
10. I only use RO water, but have never measured the TDS. I get it from a Culligan Water machine.
11. Water Changes - I do one whenever I get the chance. Usually once a month at about 25% or 10 gallons. I use Instant Ocean Salt.

Thanks,
Mike

 

[leebca]

Thanks for the thorough information.

This tang is a very active fish. Usually always on the go. I'm not familiar with corals (fish is my game) but it isn't unusual for a fish that comes in contact with an 'unfriendly' coral to be scarred or 'burned' by it. In fact this is one of the conditions that makes determining if an anemonefish might have the onset of Black Ich or just a bad day with a coral polyp.

I would watch the dark patches and see if they spread/worsen or begin to disappear. If they worsen, put the fish back into a QT alone, without the inverts, and see if the condition improves. If it does, then the corals/inverts are likely the source of its condition.

Offer the tan greens with Beta Glucan to help it recover.

For the record, the tang must have more vegetables in its diet than your menu suggests. About 80% of this tang's diet should be vegetables (nori, algae, broccoli, kelp, spirulina, etc.). Formula Two is in the right direction, but daily feeds of one or more of those greens is needed. Skip the brine shrimp even if the tang will or wants to eat it. Supplement these with soaking the food in either vitamins or fats (alternating). The Kole Tang is the lawn mower of the coral seas. They eat almost all kinds of vegetable and algae types, including the micro organisms.

Lastly, I'd say you have a very good system. I like the things you've done. Good luck!