No luck at all - Corys dropping like flies

[src]

Early this week I placed an order with my LFS for some Punctatus Corys and a few other fish, and they arrived on Wednesday. I arranged to be at the store when the order came in - I figured I would save them the stress of being put in the LFS tanks before I picked them up.

I ordered 6, so the LFS ordered about 20. When they arrived, one of the bags with 8 fish only had 4 living fish - the others were dead. I guess I should have taken that as a sign. That bag was rejected by the LFS, and my corys came out of a bag that had only living fish. The "fish guy" picked out what seemed to be some of the better looking fish, and I was on my way home. I drip acclimated them for about 45 minutes before adding them to the tank. pH 7.4, Ammonia 0, Nitrites 0, Nitrates 5, temp 78, GH 3, KH 3.

Four of the corys are now dead, and two more are on their way. The LFS has lost most of their stock as well, so I'm sure it was a bad batch. My question is, what are they dying of? Here are a couple of pictures of the two that are still (barely) alive:





Note the redness of the tail - almost all of them developed this. Also, when they died, most of them looked like they had severe fin damage, even though there are no fin-nippers in the tank (5 Rasboras, 7 Pristella Tetras, 4 Ottos and a BN Pleco). The have a lot of trouble maintaining an upright orientation - one of them spent a good bit of time sitting upside down on top of a wisteria plant, although it was still alive:



3 died outright, I euthanized one (ice), and two more remain - I'm really torn on euthanizing them. I hate to see them suffer, but if there's any chance at all I'd like to give them the opportunity.

What is killing these fish?

 

[Jchillin]

That is very unfortunate, but you did get a terribly sick shipment. It's not easy to tell exactly what the problem is but the cory that was upside down probably has swim bladder.

You may have seen this suggestion before but it is good practice to buy fish at a LFS after they have acclimated to a tank for awhile. We have no idea of how long or what distance the fish travelled prior to arriving at the LFS. Ammonia poisoning, among other issues, leads to a quick demise during this time.

If you trust this particular store and no similar issues have been present, let them know what happened and see what they can do to make you whole.

 

[src]

The last two died last night.

I took the first two corpses to the store yesterday, and they gave me the last two from the shipment that looked decent. The store's stock was pretty wiped out, too. Only time will tell if the replacement fish will make it, but they seemed better than the original batch when I added them.

I'll be taking these four in today, and will probably ask them to re-order and hold them for a week or so. The problem I was trying to avoid by getting them before they hit the LFS's tanks was a severe pH difference. The store's tanks are 6.0, while mine is currently around 7.4. That's a LOT of acclimation. I did 2.5 hours of drip acclimation with these last two, just to bring the pH up slowly and give them the best chance I could.

I'm kind of worried about the LFS's tanks - they may be suffering from old tank syndrome (if I understand what that is correctly). There's another fish store nearby that does mostly marine, but has a small freshwater section. Thier tanks seem very well maintained, and certainly don't have that aged look/feel. I may try ordering from them next time.

 

[Jchillin]

The store's tanks are 6.0, ...

Unless they have a very good reason for having a ph that low (Discus, SA exotic cichlids, plants and tons of driftwood), that is an insanely low ph for a LFS stock tank.

It's no wonder fish don't last in their stock tanks...not to mention that if they know this they are doing nothing to address it. Yes, avoid this store unless conditions improve. You should not have to be in a position to intercept fish that you purchase from them.

 

[src]

Thanks for the information - I newly back into fish after about 20 years, and 6.0 seemed low to me, but I wasn't sure it was a problem. Most of their tanks are 20's and 30 longs, and though they do have a cichlid section, most of them are Africans - I don't know what the pH on those tanks is. I just know that the 3 times I have tested their water (Pristellas, Rasboras and now the Cory's, all from different tanks) it came out 6.0.

I may just try for a refund on these fish, and get my order filled elsewhere. On the plus side, the Ottos and BN Pleco I picked up are doing well. The Ottos were intercepted in the shipment, the BN came from their tanks, and had been there a couple of months.

My next step is, obviously, a QT tank. Once I get the corys in, I'm going to stop stocking the main tank until I can set up and _use_ the QT. I want to get these guys established and happy.

Edit: Just to clarify, the test of the cory tank water was from yesterday, when I got the two replacement fish.

 

[Ky'smommy]

i keep corys at 6.6 with my discus tank. and they are all growing and healthy. No problems. To do with the low p.h. If they acclimated them properly and what not they should be fine. I would think

 

[7Enigma]

Doesn't sound like a pH shock to me, the color and behavior would lend towards a poisoning situation (since such a large amount died). What it was, I have no idea, but I'd keep a very close eye on your tank right now, especially the 2 new cory's.

As for the fin damage, even though you don't have fin nippers in the tank, most fish will canabalize a dead fish. Normally the fins and eyes will go first, and if it happened while you slept, you wouldn't have seen it.

 

[src]

I just took the dead ones to the store during lunch, and he credited me the full order, even though I still have 2. He said he will re-order next week, and keep them QT'd for several days to make sure they are healthy before he sells them. By then, I should have my own QT tank set up, so they _will_ be healthy before they go into my main tank.

I mentioned the pH, and he was surprised that it was that low. I'm guessing they don't test the tanks as often as we do. He did at least have a log of the water changes, and the last major WC on those tanks was on the 11th. Considering the stocking levels at most stores, 2 weeks seems to be a long time between major water changes.

 

[7Enigma]

How did you measure the pH of the water from the LFS? Did you measure it by testing the pH in the bag before you put it in the tank to acclimate? How long is your drive from the store to your house?

Basically what I'm getting at is the CO2 produced by the fish in the bag if in for a while will drop the pH of the bag water, and would make it look lower than in fact it is. I'd take my liquid test kit TO the LFS and do a quick test right there to see what the pH actually is..

 

[src]

I had them test it at the store. The drive home is about 20-25 minutes. When I get home, I add a little tank water to the bag, then start the process of pouring a little bag water out, adding some tank water, rinse, repeat, with occasional tests to see how the process is going.

I will say that the LFS water is _heavily_ buffered. It resists pH changes like nothing I have seen before. My usual process is dump 1/2 - 2/3 of the bag water out, add some tank water, wait, add more tank water, wait, etc., until I get t the point where I dump 1/2 -2/3 of the bag water out again. After 3 cycles of that, the pH of the bag water was only up to 6.8. Like I said, it took about 2 1/2 hours last night to introduce the fish. I just wish I had gone slower with the first batch, although I doubt it would have made much difference in the outcome.