Black Ghost Knife--mysterious areas on skin

[mickitiffen]

I recently solved a Nitrite issue and got my paramaters down to 0. pH is still low. Tried the tablets-did nothing. In tank are 2 gouramis, 2 cory cats and ghost knife. 20 gallons. Have live plants, coral and driftwood.
2 days ago the BGK was staying in one spot, rather vertical and seemed to be breathing fast. He is very active, swimming fast and gobbling up blood worms every day. I notice a mysterious area on his skin that looks almost like a spider web. Any idea about what that might be and what I should do about it. As I said the BGK is acting very healthy the past 2 days and seems fine but I am worried.

 

[dkpate]

Well first of all, you need a much bigger tank. My BGK grew from 4-8 inches in about 6 months.
My BGK also got these weird faded spots on him, and I didn't know what they were, but they eventually went away.
I would just keep an eye on the spot, and make sure it doesn't get bigger or fuzzy or anything. Keep the water really clean also, like double up your water changes. I hesitate to use meds on the BGK since he's "scaleless."

 

[mickitiffen]

OK. What size tank do I need? The water chemistry was good except for pH is low--it was like 6 and maybe it is inching towards 7. I used API pH increaser at a low dose. The LFS said that I should remove some of the gravel, clean the lower level real well bc he thinks there is too much stuff there and that's causing the pH to stay low. Now the fish is hiding. I used MarOxy per the LFS advice.

 

[dkpate]

You will need around a 100 gallon tank, 75 at least, since the BGK can get to 18 inches if kept correctly.
Don't mess with the pH, it does more harm than good. Fish can adjust to the pH, and swings cause more shock. That pH increaser is like putting a band-aid on a broken arm. If you do water changes once a week, your pH should stay around the same. The coral you have in there could be the culprit too, but I don't remember if that makes it go up or down, I think up, so that's not a bad thing.
The pH adjuster could also be what is causing the markings on your BGK. I remember someone saying their fih was acting weird, and it was because of some algae remover they used. The pH swinging could be causing the marks too.
Just do a couple water changes, and see if that helps him out. And get that bigger tank as soon as you can.