please help!! sick skunk corys??

[wanderer_k8]

Hey guys,

Last week, I purchased 3 skunk corydoras and 1 otocinclus for my 20G tank. I am planning on eventually getting bolivian rams and maybe another oto/more corys also. Everyone seemed to be behaving fine, the 3 little corys were constantly swimming and scurrying about the bottom adorable as ever. Yesterday evening though, I noticed that one of the corys was just resting in the gravel in one spot while the other 2 were swimming around. At first i thought he wasn't moving, but when I looked closely he was breathing, but his breathing seemed to be slower compared to the other 2. This morning he had moved to a different spot, but was still sitting on the bottom even when I fed them breakfast, he didn't even move to eat. I don't notice any signs of sickness like fungus or ich or anything like that that I could see, but I did notice that he is very pale and has lost that pinkish tint that the others have. Tonight he didn't move to eat again, and now I'm noticing one of the other corys is starting to act strange too..with the same listless behavior and not really interested in food. He doesn't look too sick as far as his color goes compared to the other one though. I'm worried they are going to keep getting worse, or the other cory will start showing the same behavior. ):

My water params areusing API 5in1 test strips & API liquid ammonia test kit)
temp: 77 F
GH >180? (strips don't go any higher than 180)
KH 80
PH 7.5
N02 0 ppm
NO3 20 ppm

My nitrate levels were a little high friday morning (40ppm), but after doing a pwc they were back down to 20 ppm later that day. Are these params ok for corys? or could it be the water quality?? Is the pH or nitrates too high?

Could I be overfeeding/underfeeding them?? Im still trying to get a feel for how much/when to feed them.. Ive been feeding them 2x a day, once in the morning after turning the lights on and again at night after turning the lights off (lights stay on 11 hrs). I alternate between aqueon shrimp pellets, hikari algae wafers, frozen bloodworms, and pinch tropical fish flakes.. I also put blanched cucumber in for my oto so im not sure if they nibbled at that as well.

Like I said i'm new to owning corys, and I don't know much about their behavior, but I do know this behavior isn't normal and they are unwell.. Does anyone have any ideas as to what may be wrong with my fish, or suggestions on what I could do to help these little guys? Am I doing something wrong? I plan on doing another small pwc with prime tomorrow..

Id appreciate any feedback!! After owning them for only a week I've already fell in love with this species, and Id really hate to lose them!! ):

Thanks!!

 

[Delapool]

Hi, welcome to the forum

How is your tank going now?

 

[Autumnsky]

Hi and welcome! How long has the tank been set up?

 

[wanderer_k8]

Hello! thanks for the replies! My tank has been set up since September. Unfortunately one of my corys did die within a few days But the other fish seem to be doing alright now, they are swimming and eating although I do notice they often rest in the gravel. I read though that this is normal for corys. I'm not sure what it was that was wrong with my fish.. im thinking maybe he was just weak when i got him from the fish store?

 

[Autumnsky]

Could be. If it was a wild caught fish, they have to go through a lot to get to us.

How often are you doing pwc and what are you doing with your filter pads? Do you rinse them in tap water? If so, if you have BB (beneficial bacteria) in them they will be killed off with chlorine and chloramines. You may already know that but it is important in case you didn't, to use old pwc tank or treated water.

Welcome to Aquarium Advice!

 

[Eggheadfish]

Hi wanderer,
Do you treat your water for chlorines and chloramines during water changes?
I love me some cories
Just a few comments:
Cory cats and otos are shoaling fish. It's preferable to keep them in groups of six or more
Additionally, it's a smart idea to quarantine new fish in a separate tank so you can monitor them for illness before adding to your main tank
Depending on where the cories came from, there could be a number of inherent issues. Without any other outward signs it's difficult to say. Wild caught cories can often come to you hosting internal parasites or flukes. Do they look thin? Are they scratching themselves on anything?
Also, cories release toxins in stressful situations as a defense mechanism, so if they're in a bag for prolonged periods they can often harm themselves in the process.
Weak stock can be another issue.
Are their fins clamped to them at all or standing upright? Is there any fin damage? Redness around the gills?
I hope everything gets sorted out, these are great fish to keep.

 

[wanderer_k8]

Hey guys, thanks for the advice. To answer your questions, I do a 25% pwc once a week and I use seachem prime to treat my water. I also rinse my filter pad in tank water only.
I am planning on getting more cories and otos to keep them company, but I want to make sure I got everything sorted out in my tank so I don't pass on any illnesses to new fish. I like the idea of quarantining new fish, I will definitely look into getting a small tank for that.

Just an update since my last post:
Another one of my cories started showing the same symptoms as the one that died.. it completely lost its' color (the black stripe on his back was almost completely faded),cloudy eyes, no interest in eating, got extremely thin and just sat at the bottom of the tank all the time. My other cory and oto also developed cloudy eyes and seemed to be less interested in food and were acting more lethargic than usual. All 3 fish also seemed to develop a reddish color around their gill area.. although I know cories have a slight pinkish color on their sides, so it was hard to determine whether this was normal or just the lighting or something.

After talking to the guy at my LFS, we figured maybe it could be some kind of internal bacterial infection. I decided to treat my entire tank with Furan-2. I immediately noticed that the sickest fish got his color back and started eating again. The cloudy eyes also went away and they are all now more active.

Its been 2 days since I finished treating the tank, and I hope now I am in the clear. I do still see both my cories and my oto resting at the bottom of the tank pretty often, but I read that is normal behavior for them to take rests throughout the day? Yesterday, when I looked closely at their fins to see if they were clamped, I noticed that the tail fins on the cory that was sick seemed to be damaged, like the ends were partially gone. Could it have been fin rot? Does anyone ever have problems with otos or other cories bullying each other? He is smaller, so I hope they did not get damaged that way.

 

[Autumnsky]

What kind of test are you using to test the water? No testing? Test strips, lfs testing, or liquid test like API; for all Ammonia, NitrIte and NitrAte? Do you know you PH and GH/KH?

 

[Eggheadfish]

Glad to hear things are improving. Cories and otos are docile, bullying wouldn't be an issue here. Damaged fins could be present as a secondary problem to the bacterial or parasite infection, I would say keep the water clean and give it some time, they should grow back assuming the problem is resolved.