Longfin corys looking weak and then dying

[distant2nd]

I got two "longfin" corys from the local mom and pop pet shop right before thanksgiving 2021, one of them died within a month, it was fine for a while then I noticed it looked like it was withering away, and within a day or two later was floating on its side, still alive for another day before it passed. the other longfin seemed to be doing well until last night, it looked slightly scrawny compared to its usual, and now is on its side, still alive.

I've been feeding them and my other corys algae chips, and one of my corys is over 11 years old now. I recently did a water change, about 40%, using my RO filter water we added to the sink in the fall. Outside a very low KH, all the other parameters are coming back normal. My PH fluctuates a little , from 7 to 6.6, but nothing too crazy.

The first to go out of the new batch was another type of cory I bought in that same batch. I don't think it lasted 2 weeks. The other one of THAT kind seems to be ok still, tho its a skittish lil thing. I;m at a loss as to why these fish are dying off. Do they require something additional besides the algae chips? I noticed my tank algae has been a lot slower at growing in, as I'm assuming the corys have been taking care of that issue. I got the RO filter because I was afraid that the reservoir water had too many dissolved solids in it. It does absolutely soften the KH to zero, and I've been using some alkaline buffer, only when the PH is a little low, to maintain that.

I never had these issues where I used to live, where the water was supplied by American Water. Water was perfect every time, just had to add tap water conditioner and done. I'm afraid to get new fish, I don't trust the water. =(

 

[bored411]

I got two "longfin" corys from the local mom and pop pet shop right before thanksgiving 2021, one of them died within a month, it was fine for a while then I noticed it looked like it was withering away, and within a day or two later was floating on its side, still alive for another day before it passed. the other longfin seemed to be doing well until last night, it looked slightly scrawny compared to its usual, and now is on its side, still alive.

I've been feeding them and my other corys algae chips, and one of my corys is over 11 years old now. I recently did a water change, about 40%, using my RO filter water we added to the sink in the fall. Outside a very low KH, all the other parameters are coming back normal. My PH fluctuates a little , from 7 to 6.6, but nothing too crazy.

The first to go out of the new batch was another type of cory I bought in that same batch. I don't think it lasted 2 weeks. The other one of THAT kind seems to be ok still, tho its a skittish lil thing. I;m at a loss as to why these fish are dying off. Do they require something additional besides the algae chips? I noticed my tank algae has been a lot slower at growing in, as I'm assuming the corys have been taking care of that issue. I got the RO filter because I was afraid that the reservoir water had too many dissolved solids in it. It does absolutely soften the KH to zero, and I've been using some alkaline buffer, only when the PH is a little low, to maintain that.

I never had these issues where I used to live, where the water was supplied by American Water. Water was perfect every time, just had to add tap water conditioner and done. I'm afraid to get new fish, I don't trust the water. =(

I don't know anything about the water questions you have, but cory don't actually eat algae much. I would get them some sinking pellets with fish as the first ingredient. I used to do algae pellets as well but found out that (unlike pleco) they don't really get all they need from algae chips. I feed my green and peppered cory Omega One sinking shrimp pellets.

And what are your other levels? Ammonia? Nitrite? Nitrate? I usually don't bother testing my PH, KH, and GH much because I find trying to alter them all the time to get them to my perfect ideal number just stresses the fish out by me changing things back and forth too much. Others on here might have better advice on that but I don't think those levels are killing them off.

 

[KingOscar]

Cory's need meat in their diet, but many products called "algae" wafers/chips/whatever actually do start with this ingredient. I'm gonna say that your 11 year old Cory pretty much says you can rule out food as a problem. Still, it may be good to adjust their diets. They love frozen worms.

 

[distant2nd]

Cory's need meat in their diet, but many products called "algae" wafers/chips/whatever actually do start with this ingredient. I'm gonna say that your 11 year old Cory pretty much says you can rule out food as a problem. Still, it may be good to adjust their diets. They love frozen worms.

Thanks, I'll hunt that out, I think I'm going to take a water sample to petsmart tomorrow. maybe there's something the API tests aren't telling me.

 

[Tryne]

I have a dozen pygmy cories and 6 panda cories. I give them 1 Supervit Tablet B every saturday and 5 Hikari sinking wavers every wednesday. Plus the food for shrimp and chilis which they of course also snack on. Cories also go pretty crazy on live Artemias as they end up stuck on surfaces in the tank after a while.

 

[distant2nd]

Last night, the lil long fin cory was on his side or upside down on the bottom of the tank, but fighting it. He would dart across the tank periodically, swimming sideways or upside down. I let him be and wait and see what happened. I added some Stress Coat as well as bumped the PH up a bit. Today he's upright, and has moved to a few different spots, but taking it easy. I also added some standard tetramin fish flakes to the tank, so they'd sink and they could get some fishmeal and other nutrients as suggested. I put an order in for a 3 pack of hikari sinking wafers, should be here on Sunday. I now know that sinking wafers and algae wafers, even from the same company, are different things!

So our little cory friend lives another day, though the edges of his fins looked a little reddish? We have a live plant growth light in the tank so it might be a bit accentuated. Will be taking the water to petsmart tomorrow for testing all the same.

 

[Blacksheep1]

What breed is a long fin Cory ? Do you have a picture ? I’m glad your little guy is doing better ! He may need more friends to help him feel comfortable , which again a picture will help with id’ing which species to get.
Personally I’d suggest not chasing a ph level with chemicals , it’s a losing battle and just stresses the fish long term. You could research crushed coral in your filter to help , if needed . But again that would depend on the species you have

 

[bored411]

What breed is a long fin Cory ? Do you have a picture ? I’m glad your little guy is doing better ! He may need more friends to help him feel comfortable , which again a picture will help with id’ing which species to get.
Personally I’d suggest not chasing a ph level with chemicals , it’s a losing battle and just stresses the fish long term. You could research crushed coral in your filter to help , if needed . But again that would depend on the species you have

Long fins are peppered cory.

Last night, the lil long fin cory was on his side or upside down on the bottom of the tank, but fighting it. He would dart across the tank periodically, swimming sideways or upside down. I let him be and wait and see what happened. I added some Stress Coat as well as bumped the PH up a bit. Today he's upright, and has moved to a few different spots, but taking it easy. I also added some standard tetramin fish flakes to the tank, so they'd sink and they could get some fishmeal and other nutrients as suggested. I put an order in for a 3 pack of hikari sinking wafers, should be here on Sunday. I now know that sinking wafers and algae wafers, even from the same company, are different things!

So our little cory friend lives another day, though the edges of his fins looked a little reddish? We have a live plant growth light in the tank so it might be a bit accentuated. Will be taking the water to petsmart tomorrow for testing all the same.

I would just let the PH do its thing. Again, I feel that bouncing the PH back up repeatedly is causing more stress to the fish when they can do just fine with it where it's at, even if it's not exactly at the right range for the fish. Definitely let us know what your water test results come back as. The ammonia/nitrite levels are usually the most important as they can kill your fish easily.

I would also get Melafix and/or Pimafix at petsmart while you're there. Red edges to fins usually means fin rot which could be caused by a multitude of things from poor water conditions to getting nipped at by fish to scraping on something. A large water change would be smart too. I'd do about 50% water change, dose with the melafix/pimafix (or both if you can) and once you know what your levels are at then you can work on that too.

 

[distant2nd]

Thanks, he seems to be ok most of the time, but occassionally lying upside down, then getting back up a bit later and looking normal. He looks slightly bloated. Could it be overfeeding? When he's upside down, he looks like me on the couch after Thanksgiving dinner. =D I've been dropping one chip per fish for ages. Never been a problem before.

I would just let the PH do its thing. Again, I feel that bouncing the PH back up repeatedly is causing more stress to the fish when they can do just fine with it where it's at, even if it's not exactly at the right range for the fish.

My PH gradually drops over time, I've heard that's fairly normal, so I correct it with water changes and Seachem Alkaline Buffer. I cannot get the KH to rise much without it, the RO system really pulls the KH down.

What breed is a long fin Cory ? Do you have a picture ? I’m glad your little guy is doing better ! He may need more friends to help him feel comfortable , which again a picture will help with id’ing which species to get.

Definitely a peppered cory, but a longer flowing fin variant. The 11 yr old fish is also a peppered cory, who the kids have dubbed her as "mama fish" . There's also one leopard cory in the tank. If I can get the tank to stay stable long enough, I generally stock zebra danios and glofish variants as well. In the past, the corys and danios lived well in harmony. =)

 

[bored411]

Thanks, he seems to be ok most of the time, but occassionally lying upside down, then getting back up a bit later and looking normal. He looks slightly bloated. Could it be overfeeding? When he's upside down, he looks like me on the couch after Thanksgiving dinner. =D I've been dropping one chip per fish for ages. Never been a problem before.

My PH gradually drops over time, I've heard that's fairly normal, so I correct it with water changes and Seachem Alkaline Buffer. I cannot get the KH to rise much without it, the RO system really pulls the KH down.

Definitely a peppered cory, but a longer flowing fin variant. The 11 yr old fish is also a peppered cory, who the kids have dubbed her as "mama fish" . There's also one leopard cory in the tank. If I can get the tank to stay stable long enough, I generally stock zebra danios and glofish variants as well. In the past, the corys and danios lived well in harmony. =)

You are probably overfeeding. What I was doing with my 2 albino cory (before they passed) was breaking up an algae wafer in half. So they got 1/4 apiece. I have two green cory and a peppered cory right now and I don't give them wafers at all. I give them sinking pellets. About 2 a piece since they're small. Mind you, any floating fish flakes that reach the bottom are also typically scooped up by the cory. So they're getting fed more than you think most of the time.

And I don't know anything about RO systems so I can't help you there. I typically don't worry about the GH, KH, PH of my tanks. I use tap water and just dechlorinate it; add some Prime (for the 0.25 ammonia my tap always has) and Stability and that's it. I was trying to adjust PH before and worried about the GH and KH but the fish I have don't seem to have issues with it. I think certain plants can have issues for sure, but I've not had problems with my fish.

 

[DoubleDutch]

There are several species that have man made longfinvariaties.

The instabil waterconditions and the poor diet (I call this algaewaferitis) ate probably culprit.

If that is solved get more Corys.

Some pics would be appreciated and probably give a better insight.

 

[distant2nd]

Just an update, the lil cory is doing fine. Switching to the sinking wafers seems to have made him more active again too. =)