Cories dying again

[VioletThePurple]

This is extremely stressful. Now out of my three survivors, one is on the ground not moving again. I went on vacation so I couldn't monitor the water everyday. During the vacation, there was no food given, and lights off. Water parameters turned out fine according to the card that came with it. Can't test for ammonia because it doesn't test for it. Was doing water changes daily prior to vacation and just did another today. Cleaned out the filter before with tap water, later informed that could be dangerous. Cleaned out filter today with tank water. Last time a cory was on the ground, I put him in a quarantine tank, did a small water change and I guess that killed him because he died soon after. So I won't be using the quarantine tank for them again because I feel like they're more vulnerable in there. I thought they were sick but was told sickness wouldn't kill them off that quickly. They die a day after showing symptoms despite water changes.

This happened before. I couldn't figure out what was happening and there was only a sole survivor. I had to get more because they're schooling fish and after several months and regular water changes it's happening again. Maybe once I'll inevitably have my sole survivor again or they all die off I'll stop keeping fish altogether and then just leave all the fish keeping communities. I'm doing everything I'm supposed to and I still can't keep fish alive. It's highly discouraging and stressful. I should just say screw it because clearly I must be a horrible fish owner and I don't deserve fish so I've been wanting to just dump out the tank, throw everything away, then just have a blank empty space as a reminder that I'm a complete failure at keeping fish alive.

 

[connorlindeman]

Take a deep breath. You can figure this out.
Did you say that you cleaned the filter with tap water again today? Why?
Is this the same tank that has the betta from the other post?
What are your water parameters?

 

[VioletThePurple]

Take a deep breath. You can figure this out.
Did you say that you cleaned the filter with tap water again today? Why?
Is this the same tank that has the betta from the other post?
What are your water parameters?

I meant to type tank water, I cleaned it with tank water but I mistyped. Yes, this is the same tank. Nitrate 20, nitrite 0, ph 6.5, didn't test for ammonia. I shouldn't have to tell you though, the card it comes with literally tells me what water parameters are safe.

 

[connorlindeman]

Is this the same tank with the betta?
The ph does seem low for catfish

 

[VioletThePurple]

Is this the same tank with the betta?
The ph does seem low for catfish

Yes, it's all in the same tank. I only have one main tank. I know it's a little low, I've been trying to boost it with partial daily water changes. Also those results are old, it's been about a week since I tested so they may not be accurate.

 

[connorlindeman]

Yes, it's all in the same tank. I only have one main tank. I know it's a little low, I've been trying to boost it with partial daily water changes. Also those results are old, it's been about a week since I tested so they may not be accurate.

Are the nitrite and nitrate tests old as well? If so, please test again for all of them including ammonia.

 

[Byron]

There is nothing wrong with the pH at 6.5, in their habitats these fish live in much more acidic water. A fluctuating pH is however very stressful, are you doing anything to adjust pH? By which I mean using substances/chemicals/additives? We really need more data on this tank, if this is in another thread can you post the link so we can see it.

Nitrate at 20ppm is high, but not on its own going to kill the fish like this. Is the nitrate occurring within the tank, or is theree nitrate in the tap water? Two different causes, so two solutions, depending.

 

[VioletThePurple]

Are the nitrite and nitrate tests old as well? If so, please test again for all of them including ammonia.

Tested again, everything is about the same but the ph is a little darker, might be at 7. I would test for ammonia but I can't right now, I only have test strips. I'll get an ammonia test next time I'm at the pet store.

 

[VioletThePurple]

There is nothing wrong with the pH at 6.5, in their habitats these fish live in much more acidic water. A fluctuating pH is however very stressful, are you doing anything to adjust pH? By which I mean using substances/chemicals/additives? We really need more data on this tank, if this is in another thread can you post the link so we can see it.

Nitrate at 20ppm is high, but not on its own going to kill the fish like this. Is the nitrate occurring within the tank, or is theree nitrate in the tap water? Two different causes, so two solutions, depending.

I only starting trying to adjust the ph when I noticed the cories odd behavior. I did buy something but I don't remember what it was called. It looked like bubble balls, and the product said it helped with water start up and maintenance, stated it can't be overdosed. I don't know what other info you need, it's a 20 gallon, been set up for about two years, temp stays at 76-81F. I normally do water changes every two weeks.

I don't know if nitrate's in the tap water, but my dad uses the same tap water in his tank and none of his fish have died or had issues. All I know is that I put the test strip in the tank and that was the result.

 

[VioletThePurple]

My group of corydoras have been dying off. Symptoms are: Spine curvature, weight loss, laying on tank bottom, won't get up unless bothered, heavy breathing, and dying about a day later. Temp is 78-81F, water parameters are nitrate 20, nitrite 0, ph 7, strips don't test for ammonia.

 

[AdoraBelle Dearheart]

Maybe once I'll inevitably have my sole survivor again or they all die off I'll stop keeping fish altogether and then just leave all the fish keeping communities. I'm doing everything I'm supposed to and I still can't keep fish alive. It's highly discouraging and stressful. I should just say screw it because clearly I must be a horrible fish owner and I don't deserve fish so I've been wanting to just dump out the tank, throw everything away, then just have a blank empty space as a reminder that I'm a complete failure at keeping fish alive.

I remember feeling like this when I first started, I kept losing guppies despite working as hard as I could to have a perfect tank, and it's incredibly disheartening and frustrating. I know the pain you're going through now! Please stop beating yourself up though. You're being way, way too hard on yourself! There is a really steep learning curve to this hobby, especially in the first year or two. A lot of new info to take in, and a lot of things that can and will go wrong. But you can get through it and have a lovely, healthy, peaceful tank, I promise you. It takes time, patience and willingness to learn. You seem willing to learn and it shows that you care about your fish and want to save them, those are the important things to have in this hobby, and we want more hobbyists like that, so I hope you don't give up and brand yourself a failure.
In order to try and help, we do need a lot of info from you I'm afraid. We can't see the tank or fish for ourselves, or test the water, so all we have to go on is what you tell and show us. There are a lot of things that can go wrong, as I said above, so that's why the barrage of questions I'm afraid! But the more info you can give us, the better the chances that someone can figure out the problem and advise on how to fix it.

So to add my questions to the pile;
What's the complete stocking of the tank?
Can you share photos of the tank as a whole, and of the fish please? Both any fish that look sickly, and the rest of them ideally.
Do you have live plants in the tank?
Do you use a water conditioner when you do water changes? Do you match the temperature of the new water to the tank temp?
How much of the water do you change at a time? Do you clean the substrate?

Can you get a liquid testing kit to test water parameters? The liquid test kits are much more accurate than the dip strips, and when it comes to problems in a tank, we need accurate numbers for ammonia/nitrite/nitrate/pH etc. The API Freshwater Master test kit is popular, as is the NT Labs liquid testing kit. They seem pricy compared to dip strips, but along with being more accurate, you also get far more tests out of them, so you don't need to keep buying strips. Better value for money in the long run.

 

[AdoraBelle Dearheart]

It would really be better to keep all this info the same thread, rather than scattered threads across the forum. It gets really confusing when that happens

 

[VioletThePurple]

It would really be better to keep all this info the same thread, rather than scattered threads across the forum. It gets really confusing when that happens

I scattered because I want more answers, and it highlights specifics.

 

[Oblio]

I would begin by reducing nitrates by more frequent and/or larger water changes. That may not be the root cause of the mortality, but it doesn't help to have 20 ppm nitrate.

 

[HoldenOn]

This sounds a lot like internal parasites. Some pictures are really the only way to tell, but I have lost Corydoras to internal parasites before and they demonstrated many of those same symptoms. Luckily for you, General Cure is super easy to find and should knock out any internal issues the fish have. Remember when dosing with medicine, make sure there is no carbon in the filter. Pictures would be greatly appreciated.