dark stuff on albino cory

[dricicle]

Hi! I have a maybe seven year old albino cory (female, but I didn't know that until recently so I call him 'he') alone in a 10 gallon tank (I know cories are suggested to be in groups but my housemate won't let me get another fish). I vacuumed gravel and replaced water today.

The main concern is that he has what looks like dirt on his left side/gill; he's breathing fine and hasn't been acting weird that I've seen, but I don't know what the dark stuff is. I've attached an image below.

Regarding the tank and parameters:

It's a 10 gallon that's been set up for at least seven years, maybe more, I don't remember exactly when we got it. I started taking care of it June 2019 (the previous caretaker did a very bad job). The filter is an aquatech 10-20 gallon filter on the tank and I switched to using aquasafe plus water conditioner maybe a few months ago (used to use ozarka spring water because I didn't know about water conditioner but knew not to use tap water). I clean the tank every few weeks and usually remove about 15-25% of water. Water changes of 10% are every week or so.

Water parameters (roughly according to tetra test strips):
0 Ammonia
10 Nitrate
0 Nitrite
200 Hardness
0 Chlorine
100 Alkalinity
7.2 pH
75-78 degrees F

 

[Autumnsky]

Are you familiar with the nitrification cycle?

How often do you do water changes and how much?

In the pic it certainly doesn't look normal. But I can not tell what it is.

Are there any worm like creatures in the fills - gill flukes?

Have you added any new fish in the past few weeks / months?

 

[dricicle]

I'm somewhat familiar with the cycle, I'm currently cycling a new tank (fishless). every test I've done looks normal on the nitrate/nitrate front. no new fish and he doesn't have any worms. I went to a couple pet stores today and no one knew what it was exactly - one suggested tetra fungus guard but I didn't buy it because I wasn't sure how it'd work with scalelsss fish / didn't want to medicate without knowing what was wrong exactly, while the other told me to check ammonia with a liquid kit. the ammonia was a little above 0 (but below .25).

I do water changes kinda sporadically, but usually every few weeks. I've started doing them more recently because of this dark patch.

 

[Autumnsky]

I would get the water changes more regular and do 25% at least one time per week.

For now I would do 2 25% pwc this week, say one day and then the other the next day.

Then another after about 3 days one more, then keep up a regular 1x per week unless you notice the tests showing unsafe levels, of course do a pwc any time the ammonia, nitrite or nitrate is unsafe, until the water is safe for the fish.

This bunch of pwc's gets out the older water and gets it replaced with hopefully better cleaner water to help your fish have no unsafe water stresses to deal with, and it's body can focus on healing.

The article in my signature link has lots of useful information and about BB and the nitrification cycle. It is nice because you can go back to it as often as needed to get it figured out.

Fish illness info
https://www.aquariumadvice.com/fish-disease-index-for-diagnosis-and-treatment/

https://www.aquariumadvice.com/tips-and-tricks-for-your-fastest-fishless-cycle/

 

[dricicle]

thank you! I'm actually going to have to move him to his new tank next Saturday, so I think that might help with a clean tank. I'll keep doing water changes after a week or two so he can settle, since that's what everyone online said, unless I notice any weird parameters or him getting worse.

 

[Autumnsky]

Yes.

Gently rinse any filter media only with treated water to preserve as much BB as possible. Also the substrate only gently rinse (with treated or the top/ clear, better pwc water)

 

[dricicle]

The new tank is already set up / cycled, I used an old filter media to seed it and a plastic plant from the old tank. Should I just rinse that filter media?

 

[Autumnsky]

Only always rinse any filter media with pwc or treated water. For your filter pads only if it is weirdly gunky, just leave if most likely. Save the BB!

Are you ditching / tossing the other substrate rocks?

If so then use a store mesh media bag or 2, or the tightly netted garlic, citrus or veggie bags wash well, which can contain the stones and use a couple bags in the back for a few weeks. I hang them vertically next to the filter out flow and intake.

Doesn't look fabulous but keeps the fish well. Even used to keep one behind some plants so if I ever got a new tank to set up I could pull it right out for the job.

The stones have a good amount of BB also, and can help with the cycle.

As an example if you remove the substrate in a tank to change it to something else it pretty much always causes a mini cycle because of the BB in the substrate helping to maintain the necessary BB to handle the tank waste.

 

[dricicle]

sorry, I forgot to reply to this, we got busy packing and stuff. the new tank was fully cycled with the right parameters and I got him to the new house / tank. he died after a day though I found him on his side in the morning and he wasn't breathing or anything, not even when I nudged him with the net.

I think he was just really old, my mom told me he was probably closer to 9 years old, and the stress from the move was too much for him. like I said the previous caretaker did a bad job so he survived for longer than I thought he would.

I'm going to try to get some baby albino cories soon, because I like having fish and have the tank set up already. thank you for your help!

 

[Autumnsky]

Glad moving went as well as could be considered. It seems old for a Cory.

Good luck on future fish / Cory keeping, they are wonderful little guys!