Albino Cory, unsure what's going on

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Aquarium Advice Newbie
Jun 4, 2024
Central FL
(And please be nice. I'm just trying to save my little buddy.)

My albino Cory catfish started showing signs of low oxygen and/or bladder infection yesterday. I immediately did a non-invasive 30% water change (didn't dig in the gravel because I didn't want to stress him more) and gave him til that afternoon to see if he'd improve. He hadn't, and so I isolated him and added a small air stone along with the filter (slow flow, not powerful.) I gave him through the night and when there was still no improvement I added a general all-in-one treatment, in case something bacterial may have caused the bladder infection.

Checking on him tonight, he has this weird white area around his mouth that wasn't there before (kind of hard to see in the pic, it kind of looks like a reflection.) There's nothing in the tank with him, and he's barely moved so I don't think it was caused by the rocks, which are smooth anyway. His breathing hasn't improved and I'm worried I'll lose him.

Because I'm sure you'll ask:

• He's probably about 4 years old. Usually the most active fish in my tank.
• He was in a 20g tank before being isolated, with a few small tetras and a few other Cory's. Last introduction of fish was probably 5 wks ago. No issues with any other fish.
• Water changes are done every 3 wks or so.
• No, I don't usually test my water, because I don't generally have issues with my fish and I keep up with their maintenance. I've purchased some strips and the nitrates were slightly high in the big tank, but I wasn't super surprised because I was planning to change their water this week. I may need to do more maintenance now that the tank is at capacity. I really don't think it's a water quality issue though.
• Temp of both tanks are about 78°.

Picture of my little dude (newly named Phoenix! Cause I need him to rise from the ashes .... Er ... Maybe Poseidon is better idk lol) so the post doesn't get buried.


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Considering that they can live 5 -10 years under ideal conditions, high nitrates are not ideal conditions which can be affecting him. Did you arrive at a 4 year age because you had him 4 years or you are guessing age via other information? If you had him 4 years, the fish would be older than that because unless you got him as an egg, the average age of tank bred cories is close to 6 months old +/- . Fish do not get better over night so depending on what the problem is, the remedy can take some time and the fish will show small degrees of improvement in days/weeks. How did you arrive at a diagnosis of " Low oxygen and/or bladder infection"?
For what it's worth, Cories like higher flow well oxygenated water so I don't know that your low flow setup is going to really help him. I would increase the aeration.

If your are showing a higher nitrate level after not changing water for 3 weeks, it would be better to do your water changes more frequently. Your nitrate level can help show how frequently that should be. There is little downside to changing water frequently. In fact, in my hatchery, the water was changed daily and the fish grew well and fast. It's been my experience that changing small amounts of water more frequently has a better result than changing large volumes of water less frequently. Changing small amounts of water less frequently does not really help " clean" the water in the tank. It's like a math problem: If your nitrate level is 100 PPM and rises by 10 PPM per week and you only change 30% of the water every 3 weeks, how much are you really lowering your nitrate level? :unsure: ;)

Hope this helps. (y)
I've had him for 4 years. So likely 4.5-5 yrs. He was very tiny when I purchased him.

I assumed low oxygen because of the labored breathing, and bladder infection because he was hanging vertically on the plants/decorations.

In the 20g, there's a waterfall filter and a large bubble wall. So there is aeration through the tank. The tank he's isolated in, has a low flow filter and I added an air stone to the bottom of the tank to help aeration down there too.

Generally every 3 weeks has been fine - up until now. I've recently stocked my tank with some more small tetras, and I should've known to change it to every 2 weeks. It's around the usual time I do my tank, and so that is definitely a fault on my end. I'll try to find time to do smaller water changes every week.

From a few other forums I've posted on, several have mentioned cotton mouth due to the sudden appearance of the white spot around his mouth. I still am unsure if that's what's happening, but I'm going to get the treatment for it tomorrow.

If you have any other suggestions pertaining to the info I've responded with, I'd be happy to have them. Thanks for the info!
Cotton mouth will show as a fuzzy appearance not a spot so treating for cotton mouth is most likely a waste of time if the spot is not fuzzy. Would need to see a clearer close up pic to better advise. Are his barbels still in tact?
As for the size of the fish when you got him, if it was a runt, it would be tiny but not necessarily young. Sadly, commercially raised fish often have " runts" in their spawns but the breeders do not cull them or keep them out of the fish for sale.

As for the rapid breathing and listing on the plants, if the fish was ill, those are typical symptoms of internal disease. If the fish is still eating, a medicated food would be the proper course of action. If the fish is not eating, there are a few meds that can be used but their effectiveness is based on water chemistry so you would need to know your Ph & GH to choose the correct med. (y)
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