[Sterving]

I seem to be losing my cories. I searched this forum for simmilar cases and found some, but none shed any light on the problem.

Here's what's been happenning:

I used to have two albinos for about a year. Then, one started going "dumb", losing his bearings in the tank. I would often find him on his side or upside down looking pretty dead. When touched, he'd swing erratically for a while before dropping to the bottom again. His condition worsened over next few days until I found him dead floating at the top in the corner. He had what appeared to be a massive hemmorhage (sp?) near the gills.

I later decided to add a few more cories to keep my lone one company. I bought four "green" cories (don't remember proper name).

A week after that, the second albino cory died the same way as the first, but it took only three days or so. I euthanized him after it became apparent I could do nothing to help.

Over a month has passed with no cory deaths. I did however lose one male swordtail, but I think it was because he was harassed to death by the other.

Then I noticed that one of the four cories is not as active as the rest. Looking closely, I noticed that he seemed to have lost his buoyancy, as if he swallowed rocks. He would make an effort to swim up to the surface for a gulp of air as cories do, but rarely make it to the top. He'd then drop to the bottom like a rock. He stopped eating. I tried feeding him by bringing him food with the tweezers. He ate once a little. Soon he could barely move. I did what I thought the right thing to do: put him into deep freeze.

Barely a week passed, and another cory fell sick the same way. Three days later, (tonight) he was dead. No apparrent injuries. I did notice a little bleeding at the base of the front fins (what's the proper name for them?)

I have two cories left. No other fish or snail is affected.

I checked the water parameters and everything checks out fine. The temp is 75-76 F, stable. 45-50% weekly w/c.

The only problem I have right now is the green fuzz algae. It covers plants and sides of the tank, and I've been losing plants. I am waiting for the XP2 filter to arrive so that I can plumb DIY reactor inline and start DIY CO2 again. I will have to get some new plants too, as I have just amazon swords left and they begin to succumb too. There's also some BBA, but it's under control.

 

[Aqua Dave]

I feel your pain. I have struggled keeping cories in my tanks. All other fish do fine, but cories have always had problems. I have struggled for an explanation. I thought for the longest time it must be something in my tap water, but I don't think that is the case anymore.

I recently completely tore down my 45 gallon tank and redid it with Onyx sand substrate and all new plants. I redid it to house some praecox rainbows along with some existing danios. I've had my remaining 4 cories in a 10 gallon tank and they weren't looking too good so I decided to move them into the 45 and see what happened. Lo and behold, they are doing better than ever in the 45 with water straight from my tap.

I'm still not quite sure why they are doing so well now. I think it may be a combination of a newly setup tank along with good water movement on the bottom. I'm still struggling with water movement on the bottom of my 150, which is where I've tried to keep cories before. The 45 has much better water movement than the 150.

So you may want to evaluate the water movement on the bottom of your tank. Make sure water is circulating down there to oxygenate the water and remove dead spots. You may also want to go check over on planetcatfish.com. There are some very knowledgable people on that board.

David

 

[Alexplosive]

I put 4 albino corys in my tank and they all died within a few days. Then I bought 2 darker color corys (not sure what type). One of them died and the other one has been alive in my tank for about 8+ months now. He/She is the only cory I have in the tank.

 

[florafan]

I too had problems with corys. I got about 8 from my brother (he started with six and they bred like crazy) and they were fine for a few months and then they started dying off - with symptoms very like the ones Sterving described. I also notice that a few of them, as they really start to deteriorate, would twirl and whirl through the water. It looked like neurological damage, or some bug that attacks the nervous system. I also have guppies and 2 amano shrimp in the tank and they are perfectly fine. I tested all water parameters and they are all fine. I am puzzled as to what caused this. If anyone can come up with possible causes, please post.

 

[Sterving]

So you may want to evaluate the water movement on the bottom of your tank. Make sure water is circulating down there to oxygenate the water and remove dead spots. You may also want to go check over on planetcatfish.com. There are some very knowledgable people on that board.

David

I have a dedicated powerhead with horizontal spray bar that creates circulation throughout the tank. It pushes water from the surface across the length of the tank, down to the bottom then back to the other side of the tank. I can see how the flakes that I feed them fly around the tank. So I am pretty certain the lack circulation is not the culprit.

I will certainly check out planentcatfish.com for more info.

 

[gointomexico]

Is there any salt in the tank? I have to say that I lost one albino cory, but all the other cories that I have had has done well. My albino cory just swam and swam like crazy, I dont think he ever ate. after about a month, he died, and I have never figured out why.

 

[pittiepride]

I have has cories do similar things and figured it was the gravel or poor water circulation. Lots of hemmoraging, loss of babels, erratic swimming. Just decided to do loaches instead. Sorry can't be more help.

kara

 

[rodney]

I too had this problem with two peppered cories. But, I think I found my problem. This only happened to mine after I did water changes, so I cut from a 30 to a 20 percent water change. This cured mine wierdly enough. So it could be all the stress form your big water change. I don't think that water movement plays to big of an issue because I had a junky wisper filter on my tank.roud:

 

[kevbshields]

Having battled my own "Cory Tank of Death" about three years ago, I concluded it was either salt or a virus. Although I've never researched the issue, the sign/symptoms seemed very consistent with viral death . . . sort of slow, deteriorating death (with an initial fish or two) then very swift death of members of the species. Usually no obvious symptoms onto the onslot of generalized, vague symptoms and nothing environmental to account for the behavioral/health changes. I also theorized it viral because I treated the fish with antibiotics (broad spectrum) and "baths" in anti-parasite treated water--this was not done at one time, but over the course of my losing battle. By all accounts, had it been much of anything else, my treatments would've made some dent in the progression of deaths.

However, over the course of 6-8 months, I wiped out an entire 15-gallon stocked with cory cats. Regardless of what attempts I made, the "bug" seemed resistant.

Cories absolutely will not withstand (as far as I know) any amount of salt in the water. Moreso than Tetra, they are not tolerant and will succumb easily.

I know these things may have been mentioned by other folks, but thought I'd share my own frustration over a similar mystery/scenario.

Good luck to you.
Kev.

 

[AmoAquafish]

Do you have gravel or sand? Corys really seem to do better with sand, so much so I would never keep any with out it. Probably not what is causing the problem but I thought I'd mention it.

 

[Sterving]

I hever add salt to my tanks.
I am certain circulation was not the issue - i had a dedicated powerhead for that.
I have eco-complete; the cories still dug in it - no barbel damage noticed.

I have since replaced the filter and the powerhead with an XP2.

 

[Aqua Dave]

Since this thread got resurrected I'll post a follow-up. The 4 cories I moved into my 45 gallon tank are still alive and doing ok. A couple of them had some serious barbel damage when I moved them and it has not noticably healed, but they root around in the sand just fine and seem to be eating ok. I'm using tap water for my water changes so it seems that was not the issue. I still have no idea why they had issues in my other tanks. Not much help I know, but at least it shows there may be hope.

David