[Empress Akitla]

I don't know what's up. Is it just me? Am I doomed to keep only guppies and bettas?

The first cories I got were three peppered juveniles from PetCo (I am so done with getting fish from these guys) and a week later I got three adult peppered cories from my LFS. The adults were perfectly healthy. Two from PetCo died that weekend, and so I got two more from them (their 30 day guarantee you know). Also bit the dust a week later.

And now I have no cories. Went on vacation and came back to none. No other fish in my tank shows any signs of illness and my parameters are normal. My stock are fancy guppies, three platies, and a bristlenose pleco.

Tank - 29 gallon, moderately planted with crypts and anubias
pH - 7.2
Nitrates - 5-10ppm
Nitrites - 0ppm
Ammonia - 0ppm
Temperature - 78F

Am I just getting bad stock? Like I said, the adult cories appeared very healthy and acted normally in my tank. Nothin wiped out the entirety of my tank, just the cories. Help?

 

[RyRob]

If your only issues are the dying corycats, I'd chalk it up to bad/sick livestock on PetCo's end. I don't have a PetCo local to me but I do have PetsMart that takes decent care of their fish. When you go there next, inspect the tanks and use your best judgement. My other LFS neglects their tanks badly, leaving 4-6 or more dead fish stuck on the intakes and then usually some just drifting around the tank. Needless to say, I don't purchase fish from them.

If most (like 90%-95%) of the fish look healthy, are active, and curious when you get near the tank, I would pick the healthiest looking specimens and only the healthiest no matter how clean the tanks were. If the tanks look neglected, dirty, and sick, don't buy fish from those tanks. Look for fin rot and fin development, breathing habits, behavioral habits, monitor their movements and make a decision on whether or not to make a purchase. And don't be shy to make the employee gather the specific fish you want either, it is their job and if they won't, get a manager and if still no customer service, don't give them your business.

Also, be conscious of what day they get their fish shipment. The transportation process is very stresfull on fish and it could be that you are buying severely stressed out fish which in turn can make them sick and contribute to developing diseases and illnesses. This, of course, also has a lot to do with the store they are being delivered to. Putting fish that are stressed from transportaion into neglected tanks is a sure fire way to kill them. It takes longer for them to recuperate, if at all, and it can take weeks/months for certain illnesses to take effect even if they were eventually put in a healthy environment. If PetCo isn't taking care of their tanks, you're pretty much screwed from the get-go anyways, but not always.

 

[GreenAcres]

I haven't had trouble with any fish except for cories. They just never thrived in my tanks. We have really hard water, but other people in my city didn't seem to have any problems with them. When I finally gave up and gave away my remaining cories to a friend in another part of the county, they spawned for him. I lived in an older neighborhood and I came to the conclusion that my water was just different. I figured that something somewhere was leaching something into the water that cories don't tolerate very well. Everything else does great in my tanks, but I just can't seem to keep cories. It's a shame because I love the little clowns.

My stock at the time otherwise was similar to yours and they thrived and bred without trouble.

 

[BrassFinger]

I've been having a few issues with corys as well but not nearly as bad. I have a tank that's pretty well dedicated to my corys aside from a BN pleco and a couple of random guppies that have survived everything including a Firemouth cichlid and a bad case of ich (long story - wasn't my tank).

I started with two spotted cory (Ambiacus from what I can tell) from my LFS. They started out in the rehabilitated tank with the Firemouth (minus the guppies which were in another tank by now) but the FM didn't appreciate the corys swimming right through his "house" cave. The corys, naturally, don't care where they go, but I could see that this wouldn't be good so I moved them to the separate guppy tank temporarily. I then went about setting up a spare 10 gal. tank and getting it cycled as a more permanent home for them. I finally re-homed the FM with my LFS as she was simply getting too big for the tank even though she got along well with the BN pleco and the group of tiger barbs. I brought home some additional corys to add to the tiger barb tank and the barbs weren't aggressive to the corys at all but instead relentlessly followed them waiting to pick up any food scraps they dislodged as well as piggishly eating every bit of food long before it could hit the bottom.

So rather than having hungry corys and fat barbs, they were moved into the 10 with the rest and were all fat and happy in the sand and plants. I then added three julii (one from Petco, two from Petsmart) and a few weeks later moved everyone into the current 20H. They were all doing very well until recently when I lost one julii and a few weeks later, another. The first was overnight and the other the next day, both after separate weekly 20% water changes and a dose of regular Flourish (not Excel). I use 75% RO/25% treated tap (very hard) water. No symptoms of any sort, just boom, dead. I thought it was the Flourish immediately, but I can't imagine a proper dose having this drastic of problems with corys?

Water is perfect, temp is good, food is good, filtration good. I'm not an expert, but I know enough to have done my due diligence. No other fish showed any sort of issues whatsoever until the past few days when I noticed one of the spotted corys (leucomelas) getting very thin with clamped ventral fin and not having any appetite. I started treating the tank with Paraguard this past weekend but last night I was alarmed enough to take him out and give him a dip treatment in it. He looked pretty poor and I didn't expect him to make it but this morning he was still going and his fin wasn't clamped nearly as much. He swims normally, just lethargic. It's possible that he wasn't well from the beginning and now it is finally catching up with him in the 6 weeks or so since I brought him home.

The point of my long story is that I feel a little helpless because I have no idea what I might have done (or not done) to cause it. At least I have symptoms of something wrong with this last case, but the others, none at all. Reading GreenAcres post again, the julii's didn't seem to thrive, either. They are quite small and haven't seemed to grow much, even though they were active all the time (as the remaining one still is). I also live in an older neighborhood, and so far I've not seen a single hint that any of them are thinking of spawning. Odd, but I'm not trying to induce it, either.

Maybe they are highly sensitive to certain chemicals or toxins? I read where someone was having fish die off when filling the tank from a new garden hose and after switching to a drinking-water-safe hose the problem went away.

Chris

P.S. I wonder if running the tap water through a carbon filter (like one of those in-line icemaker or drinking water filters) might remove any potential toxins or chemicals that could be coming through the tap (including chlorine and chloramine)? My local water (city well) is tested yearly and all the results look fine.

P.P.S. What about fluoride? It's good for our teeth, but what about fish?

 

[houseofcards]

I must admit, I've been doing this a long time and I can not keep Corys. Every time I've attempted them they do not last and all other fish are fine. I've tried them on ADA Aquasoil and Eco-Complete. I might attempt them again on a sand substate, but not for a while.

 

[SNAXX]

I've kept Corys for many years. Never bred them. There's a few things you can do to give them the best chance at living a long life in your tank.

The most important thing besides good water quality is making sure they're getting enough to eat. It may look like they're eating plenty becuase they sift through the substrate all day but most of that is just natural behavior, even during feeding time. You have to make sure food is getting down to the bottom and that you see them eating it, not just picking up leftover bits. If you have very aggressive eaters housed with them it's even doubly important. Feeding a sinking food is madatory with Corys. You know when a Cory has found a nice chunk of food because it will plant itself on the substrate and start chewing rapidly.Sometimes it takes slightly overfeeding to make sure they eat enough. That makes water changes and substrate cleaning more important as well. You don't need to deep vac the substrate but skimming over the surface and picking up detritus is very important for Cory health.

A good way to make sure they're getting enough to eat is to feed twice a day. Once during lights on, which will be mostly for the other fish in the tank. Once when the lights are off, with the goal being to feed the Corys, as they are diurnal and still active when the lights go off. Most schooling species will "sleep" when the lights go off. I usually wait about 30 minutes to an hour when I use this method, to make sure the other fish are settled down and aren't going to steal the food. This method works better with sinking foods. I use NLS Thera-A and a mix of Hikari Sinking and Algae wafers, the latter two will be replaced with a higher quality food as soon as I run out.

My latest experience with the Corys I'm currently keeping is once I used this method for a few weeks after I got them, they plumped up and I was able to stop night feeding. I believe that the issue was they weren't being fed properly at the stores I bought them from. I'm looking very closely at Corys when I hit LFS now and unfortunately this happens very often. I see alot of starving Corys in the tanks. They're really a specialty feeder, something like Otos. They need food on the substrate or they starve, the way Otos need algae and aufwuchs build up or they starve.

Water quality is very important obviously. That's with any fish. Most Corys like cooler water though. So if you have a combination of warmer temperature, not enough to eat and dirty substrate it's pretty much a death sentence for a Cory. I find the temperature being the least problematic of the 3 though, as long as the temp doesn't reach extreme highs. If you have immaculate water quality, are feeding enough and the Corys enter your tank fully healthy there shouldn't be a problem with loss.

 

[BrassFinger]

Good post, Snaxx. The feeding issue is what led me to move the corys out of the tank with the tiger barbs. I just couldn't get them any food and I swear, even with the lights off the barbs would wake up for a "midnight snack"!

Well, the good news is the little guy is doing a lot better this evening! I was expecting him to barely be hanging or worse, but instead I found him swimming around like the others, active at dinner time when the food hit the water and looks at me like nothing ever happened. Needless to say, I'm very happy! Paraguard seems to have done the trick, but I know he's not completely out of the woods yet. I attached 3 pictures - two are the much-recovered "patient" and the other is "El Gordo" who quickly photobombed the spot the other one vacated just before I clicked the shutter. You can tell he (she?) doesn't miss a meal!

Chris

 

[Viclynmastiff]

I only buy fish from breeders but when I do buy from Petco I put them in hospital tank and give them metro flakes and treat with API and they don't go into the tanks for 30 days or more. I haven't lost a fish in so long. Knocking on wood as I speak


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[AWolf]

The key to keeping corys alive for me was feeding. My Bettas eat the whole sinking pellets, so those didn't work. In another tank tetras ate food too fast and none was left for the corys either. In another tank, the Angelfish ate all of their food too. So I started feeding my corys frozen blood worms and shrimp using a turkey baster, putting it right in their face, while trying to occupy the other fish with the same food at the other end of the tank. It works, but it's a pain. I tried putting the pellets in pantyhose, where they can suck it thru as it melts, and the other fish can't grab the whole pellet and run off with it. But still other fish would crowd the pantyhose pellets and scare the corys away. I'm about to give up on keeping them in a community tank for this reason. Bummed.

 

[Nordic]

I just buy the tablet form sinking bottom feeder food. Another thing that is important for keeping corydoras is good circulation. You don't want a lot of anaerobic bacteria setting up house on the bottom.

 

[houseofcards]

The tank I had them in was very well maintained. A large tank with Oto, Kuhli, rummy nose, cardinals they all thrived in there for years. I do remember feedimg a variety of foods and made sure stuff was left for the bottom feeders. Still not sure...

 

[Clear Water]

For me going to RO water was the difference between them living and thriving. They really like soft water. I have three different kinds and they have all breed in there community tanks. I had nothing but problems when I used tap water. But my water is like liquid rock. They also respond to water changes they are happy little kids when I change water. I to feed them after dark but also make sure when I feed the whole tank some of that food makes to the bottom. They love blood worms and brine shrimp. Keep trying there worth the effort and one of my favorite fish.

 

[houseofcards]

My water is actually really soft in New York. The funny thing is I remember having Corys when I was a little kid and don't remember issues with them, now that I have all this knowledge I can't keep them. I definitely try them again as I always wanted a large school.

 

[lnstevens]

I've had corys breed in hard water and they seem to be thriving in my 75 which is slightly hard.

The biggest problem I've had in keeping Corys in the past is water quality and substrate issues. Corys well dig up pockets of anaerobic sand and the lower water tends to retain a higher amount of chemicals. If you have high nitrates, they are probably higher at the bottom, etc....

If it's a food issue I've heard of people using gelcaps to feed Corys. You might also be able to find a food your other fish don't like.

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[ichy]

I think a lot has to do with feeding as others have mentioned.

They look like they are eating all day but they may not be getting anything of nutritional value.

I feed my corys sinking catfish sticks. I think I got them from Big Al's?
The cory's line up like cattle for them and they have done very well with them.

 

[Jinduan]

Hi,

I gone through some of the feedbacks here and most of the advice are quite relevant. I have kept cories (pygmies, adolfi, panda, albino, sterbai, bronze etc) for more than 10 years. Some cories are just more sensitive to others when it comes to water quality, especially the little ones.

One advice that has not yet been given is the basic fundamental of introducing new cories into the tank (regardless whether is it a hospital/quarantine tank) or straight into the aquarium.

So far, the best method for me to increase survival rates of new cories is to:

1. Place the bags of new cories into tank (quarantine or otherwise) for 30 to 45min for the water temperature to equalise.
2. Slowly transfer water (about 15%) each time from the new tank into the bags holding the cories AFTER the 30 to 45min mark. This water transfer is to ensure the pH, hardness in your tank is equalising with the water from the LFS where the cories are housed.
3. I will keep doing this until I feel that I have the equivalent of 100% of my tank water into the water bag so that I am assured that the cories will not experience a sudden spike in pH or Hardness when they are put into the tank. This usually take another 1 to 2 hours.

So I usually take up to 2 to 3 hours before I even let my cories into the tank. I also avoid feeding too much in the first 24hours so that they are acclimatize in the new environment.

However, sometimes you may have already selected cories that are already too far gone to save them. I usually avoid buying cories that have been in the LFS for more than 1 week. The chances of them catching something in a LFS is too high and nothing we do can save them. Also cories do best in numbers above 6. I have seen 4 cories being timid... but the moment 2 or 3 more are introduced... they start swimming around in groups.

Hope this helps.