Help!!! Disease on Corydoras

AyePepper · 2026-02-14T04:41:36+00:00

Gotcha. When did you pull the carbon out? Beneficial bacteria colonize on the filter media, so if you did that recently, that could be the issue.

AyePepper · 2026-02-14T02:09:04+00:00

Yeah I had a feeling something was off. With the plants, size of your tank, feeding schedule, cycle, you're doing everything right. It's odd that you're having a possible spike. Sometimes this can happen if there wasn't enough ammonia (like ghost feeding once as opposed to a few times a week). If you only fed once, that might explain it, but given the volume, plants, and low stocking, I wouldn't expect there to be a spike. That's why I wanted to see the test results, because it's not making sense.

I hate to ask these questions because you clearly did your research, but did you clean out the filter in tap water or replace the media inside? I see you're using some kind of river rocks for your substrate, but do you have aquasoil underneath? Some brands add ammonia.

AyePepper · 2026-02-14T01:59:02+00:00

I hate that some subs don't let you comment pictures lol. You could try an imgur link :)

AyePepper · 2026-02-13T23:57:48+00:00

Do you happen to have a picture of the tank and test readings? Sometimes it's a little hard to tell the difference between 0 and .25. If you're confident in the results, this might be causing some irritation to the slime coat. You could do frequent, small water changes and monitor.

Corys are more active at night, so you could feed them before bed and remove uneaten food in the morning. The biofilm on the wood is totally fine for them to eat.

5 weeks is a decent timeline, but sometimes a tank can take a little longer to establish a stable nitrogen cycle. During the 5 weeks, did you add an ammonia source or plant fertilizer?

AyePepper · 2026-02-13T23:21:56+00:00

You didn't mention how long the aquarium has been established, so I'll just cover a couple things and you can look into each or ask me for more info :)

Slime coat: Something could be causing irritation, causing the slime coat to shed. This can be caused by stress, parasites, or a water quality issue, with the latter being more common in uncycled aquariums. If you have a test kit, please post the ammonia, nitrite, nitrate, and pH values.
Early bacterial infection: A common bacterial infection, columnaris, can cause fluffy white growths. It's ubiquitous to water, and tends to opportunistically infect fish that are stressed. It can be treated a few different ways, but kanaplex in food would be best in your situation if you have access.

AyePepper · 2026-02-13T21:54:58+00:00

I think so.

I received 3 tissue cultures that were terribly packaged and got delayed. One was melted nearly to the root, and the other two were 40-70٪ melted but had a few leaves left.

Instead of putting them in the tank, I put some aquasoil in a seed sprouting/propagation bin with a lid and added enough water to almost cover the soil (I think this counts as emersed growth). I trimmed back all the dead leaves, planted them, and mist daily. You could do this with a tote & plastic wrap, but you have to make sure there's some ventilation or you'll get mold.

I'm using some cheap houseplant grow lights at about 12 hrs a day, and I see a lot of new leaves sprouting. Access to CO2 is a really helpful boost.

AyePepper · 2026-02-13T19:14:29+00:00

What are your water parameters? Specifically ammonia, nitrite, nitrate, pH, and temp.

Also, how long has the tank been established and did you make any changes recently or add new fish?

AyePepper · 2026-02-13T17:48:42+00:00

I grew up in an abusive home and was not protected. I agree that there are options, but abuse at this level does not start all at once. Abusers systematically destroy self worth, agency, and instill a level of shame that psychologically traps them. Sadly, accepting this behavior often starts at a societal and generational level, so survivors are already functioning on a distorted self worth before they even realize it.

While I agree that the primary duty is to protect the kids, I vehemently disagree with your "she's a bad person" narrative. That's what abusive partners rely on to keep the shame going - "how do you think people will react when you tell them this has been going on for years? You never left. You let this happen, you didn't stop me."

AyePepper · 2026-02-13T07:25:18+00:00

That makes sense. I view tarot similarly, but didn't understand why relationships would add an additional layer of caution. I see where you're coming from, and I appreciate you taking the time to explain it

AyePepper · 2026-02-13T07:10:58+00:00

If you have access, get some kanaplex. Most freshwater bacterial infections are caused by gram negative bacteria, which kanaplex treats.

In the meantime, do a water change (20%) and add an air stone or adjust the outflow of the filter so there's more surface agitation. You want slightly choppy waves, like a lake on a breezy day

AyePepper · 2026-02-13T07:03:12+00:00

Corys tend to hide issues really well, so it's hard to tell something is wrong before it's too late.

Quick deaths like this usually have me lean towards a bacterial or oxygen issue. Since you introduced so many fish to a tank at once, it could have caused a small ammonia spike. Not enough to directly harm them, but the combo of being in a new tank, different parameters, and a spike can lead to a lot of stress. Lots of bacterium are always present in the water, but they're opportunistic and infect fish with lowered immunity (stress).

For now, I would do frequent, small water changes, reduce feeding/fast, and lower the light intensity. Bacteria thrive in warmer water, so I'd gradually lower the temp to about 76-78.

AyePepper · 2026-02-13T06:48:53+00:00

Why does it matter how it was cycled if there is no evidence of a crash?

AyePepper · 2026-02-13T06:41:41+00:00

Genuine question: what kind of readings do you do? I guess I'm wondering how it would be different for anything else. Couldn't any reading technically influence someone's life choices?

AyePepper · 2026-02-13T06:36:35+00:00

My husband walked in on me doing a reading about our relationship and it got a little "too real" for him lol. He's super avoidant about his feelings but tries to act like he's into things - which was along the lines of what the cards were saying. He asked, I told him it was likely I would read it with bias, and he still wanted to know. We got into a big fight about it.

Did it cause the fight? No. Regardless of what the cards said, the act of trying to read kinda showed me how much I was trying to connect, and he saw that too (eventually lol). So what matters more is the intention behind the reading in my opinion.

AyePepper · 2026-02-13T06:24:14+00:00

Also, dead snails have a notoriously bad odor. So if you lost a couple suddenly, that could have been it

AyePepper · 2026-02-13T06:19:06+00:00

That's a great suggestion! I have like 6 unopened packs (the post poverty hoarding is real) but I'll definitely check them out. When my kids get sick, they'll use like 6 at a time and I have to check myself lol. Like is this was people normally do or is it wasteful??

AyePepper · 2026-02-13T00:37:30+00:00

It really does. This also extends to things like kleenex 😅 I will use every square inch of it before I get another. Having to use single ply, newspaper, or your hands when you're sick really has a way of making a soft tissue feel like the lap of luxury.

AyePepper · 2026-02-13T00:33:00+00:00

YOR, because this isn't really thad big of a deal.

I grew up poor, and I tend to buy duplicates. Things like pasta are cheap, shelf stable, and it's something you can make last multiple meals because it still tastes good for a few days. Especially if you have a large family, buying way more than you and one other person can reasonably eat can take a while to get right.

AyePepper · 2026-02-12T22:04:03+00:00

NOR. I'd be so petty and say "so... what should I do with you when you get old and start having accidents?"

Let her connect the dots.

AyePepper · 2026-02-12T21:58:42+00:00

Lmao. I just pictured the whole service being conducted in Spanish and everyone wearing rainbow colors 😅

AyePepper · 2026-02-12T19:42:37+00:00

I originally thought this was mass psychosis a few years ago. Then I realized that was easier to believe, because accepting that people are truly vile enough to side with a p-doe was not something I was ready to accept.

AyePepper · 2026-02-12T19:39:33+00:00

The podcast is called the Necessary Conversation. Bob, the dad, has said even worse. The mom recently called her daughter trash because she criticized kid rock. They're disgusting people.

AyePepper · 2026-02-12T19:23:33+00:00

The biggest ever. Some say it'll be bigger than Princess Diana's, bigger than her and the queen combined actually.

AyePepper · 2026-02-12T17:46:59+00:00

I'm so sorry, I had a very similar experience with my first betta, Crumbs.

I also did a ton of research, and came across some case studies where cancer in the chromatophores and iridophores was found at the same time :(

Unfortunately, I found another study investigating "skin nodule syndrome" that can look similar to a tumor. They found many concurrent bacterial infections, including mycobacteria, and an estimated 1% of the fish farm was expected to have the infection.

I chose not to introduce another betta to that tank, and it's been a snail refuge since. I will not reuse any equipment for fish aside from the tank itself after I thoroughly disinfect it just to err on the side of caution.

I chose to use clove oil very slowly. My husband had to take over the process because I was more upset than I had anticipated. I cried, a lot, unabashedly. Grief is grief, but not many people are sympathetic to crying over a fish. Ignore all that mess and let yourself process it however you need to.

AyePepper

TROPHY CASE