Cory’s dropping like flies!

[ellamarie]

Hey! I recently got Cory’s for the first time and they are dropping! I got 5 sterbi, 5 albinos and 5 venazualens.

I got the albinos first (from petco before I fully understood how terrible they were) and after they were doing well I was told by a local shop I could add the others.

So far I’ve lost 3 Venezuelans and 1 sterbi, but I think the sterbi was unfortunately due to the travel stress.

My water parameters are well within the ideal range, and my albinos seem to be thriving and the sterbis are doing ok. But the others are struggling. I did end up treating for fin rot, and one of the Venezuelans that passed seemed to have tail issues.

This is my first time owning Cory’s and idk what to do! Are the sterbis and the venazualens more sensitive? Were they sick from the start?

(PS: I also did a 30% water change after finding two of the dead venazualens)

SOS

 

[GaryE]

The first question that jumps out is how you manage your water. A water change after a death is a good idea, but you should do at least that every week. If you don't, the chances of Corys falling ill (especially with fin issues) goes up exponentially. But it sounds like you are in the quarantine period. The first 6-8 weeks after you get fish they're often affected by their previous conditions, in shipping, at the wholesaler, the farm and the store.

I'm guessing and hoping you have a large tank. How big? I asked the same in your platys thread.

The fish are part of a biological system you've made. Tell us about it. Could you answer these questions:

tank size
age of tank
other fish (often a key clue)
water change routine
feeding routine
decor
temperature
water hardness

It may sound like the info isn't needed, but if you're going to get help or grounded suggestions, we need a better picture.

 

[ellamarie]

The first question that jumps out is how you manage your water. A water change after a death is a good idea, but you should do at least that every week. If you don't, the chances of Corys falling ill (especially with fin issues) goes up exponentially. But it sounds like you are in the quarantine period. The first 6-8 weeks after you get fish they're often affected by their previous conditions, in shipping, at the wholesaler, the farm and the store.

I'm guessing and hoping you have a large tank. How big? I asked the same in your platys thread.

The fish are part of a biological system you've made. Tell us about it. Could you answer these questions:

tank size
age of tank
other fish (often a key clue)
water change routine
feeding routine
decor
temperature
water hardness

It may sound like the info isn't needed, but if you're going to get help or grounded suggestions, we need a better picture.

Of course!

My tank is a 40 gallon and around 2 months old for this current setup. It was cycled for two weeks before I added any fish.

The Corys are the only fish in the tank for now, and it originally was only going to be a Cory tank. With the loses I may add something else later if I continue to have issues with the Cory’s/if my platys are not all one gender and I end up with more platys than I planned…..

I change their water once every Friday (or I plan too since I’ve only had them for around 1 1/2 weeks) and do a 30%-50% water change each time. This is followed by a water test to make sure everything is ok.

They are feed bottom feeder pellets every morning and I am currently looking for other foods that also may be good for them. Thinking something high in protein. Currently I soak freeze dried bloodworms that I have for my betta and sink them down with tongs.

They have a planted tank with driftwood and top floaters, they do have places to hide but I would like to add more in the future once the tank stabilizes.

The tanks temp is monitored by a heater and is usually at 77.

The water hardness usually sits around 120ppm.

 

[Colin_T]

pictures and video of the fish so we can check them for diseases?

 

[jaylach]

Also, unless using previous filter media that has established bacteria, 2 weeks does not sound long enough for a tank to fully cycle.

 

[Innesfan]

Yes, I agree with @jaylach. Exactly what are your water parameters for ph, ammonia, nitrate and nitrite? I have found that corydoras are among the first to suffer in uncycled conditions.

 

[ellamarie]

Also, unless using previous filter media that has established bacteria, 2 weeks does not sound long enough for a tank to fully cycle.

I used filter media from my betta tank

 

[ellamarie]

pictures and video of the fish so we can check them for diseases?

I’m not home at the moment but a friend of mine stopped in and thinks it’s fin rot! Luckily he thinks it’s still early so he did a 25% water change and we’re treating with melafix. That was yesterday and so far the sterbi I was worried about seems to be looking better

 

[Innesfan]

Fin rot is commonly misdiagnosed. It could easily be due to deteriorating water conditions such as ammonia burn. Throwing meds at a situation like this should be a last resort. Providing us with the water parameters would likely be conclusive one way or the other.

 

[TwoTankAmin]

Just an FYI re cycling. Unless you dosed the tank with ammonia after adding the Betta media, it may not have been sufficient for the ammonia load from the corys. Normally I would have recommended that you added 2 ppm of ammonia and tested to know the tank was OK to received more fish. This would have meant 24 hours after dosing the 2--m that you tested 0 for bother ammonia and nitrite. Hopefully, you might have seen some nitrate. but that would usually required a tank with no live plants as they tend to use nitrate.

While seeing nitrate is not that important seeing 0s for ammonia and nitrite is.

Also, as noted bu Innesfan ammonia can cause similar symptoms to fin rot. But, fish rot can be bacterial and/or fungal and that would mean two different treatments would be suggested. I am not a fan of Melafix. Unless the problem is fairly minor, Melafix wont help a serious bacterial infection.

Bear in mind that most pet shops want to sell you as many fish as they can. It could be that you had enough bacteria for the first few fish but adding more increased ammonia production and that would likely happen at a faster rate than the bacteria would multiply to handle it.

Doing a water change would reduce ammonia levels but would not help to get the bacteria to multiply if that was needed. So, the ammonia production would have been increased by the presence of more fish being added.