Cardinal Tetra fish kill.....

[deocder]

So I bought 10 cardinal tetras for my 10 gallon planted tank.

Day one.....1 died
Day two.....another 1
Day three...yet another 1
Today.....Betta and another tetra dead

Other inhabitants:

4 ghost shrimp
1 otto
2 panda cory's
6 Cardinal tetras

Water Parameters:
7.4 pH
78 degrees F
0 Ammonia
0 Nitrite
60 ppm Nitrate
4 dKH
9 dGH

Too much bio-load? Any suggestions?

 

[anonapersona]

nitrate and bioload and quarantine

Yes, too much bio load, that's just a 10gallon, room for maybe 6 tetras and a couple of cories and a couple of shrimp. Too bad because you had it just right stocked before you went shopping. Or maybe I misunderstood, sounded like you had 6 and added 10 or maybe you added ten and now 6 are left.-?

Then, the nitrates are too high, you ought to have lower levels than that. Makes me wonder about your lighting and other fertilization levels. You need to do bigger water changes probably. I've had an overstocked tank (15 cardinals, 6 serpae, 1 corie and otos, shrimp and plants in a 20 gallon) and I doubled the filtration on it and did 50% weekly water changes.

And, now, quarantine. If you had a separate barebottom ten gallon with a sponge filter or HOB, you could keep those new guys there for a month and if they got sick then at least you'd still have your betta.

 

[hcgirl80]

That is too many fish. 10 cardinals would need a 20-gallon by themselves in order to grow to full size.

 

[Orange]

Way too many fish for a 10 gallon.

 

[cdawson]

yeah and the nitrates are well over the safe range for any fish.
at the most you can have 40ppm and some fish will survive.

 

[Skippy]

Aside from the fish load I have also found that from time to time the stock fo Cardinals many LFS get in stock just isn't that hardy and you end up getting some losses.

 

[Faramir]

No, nitrates are not acutely toxic to the vast majority of fish even at levels well above what we're talking about here. It's important to keep the levels low, but mostly as a guage to what other chemicals are building up in the water. A few fish - Apistos, checkerboards and what have you are acutely sensitive to nitrates, but most are not. The harm done by nitrates is uncertain, but many fish live for years in water far worse than this.

This study - http://www.ncbi.nlm.nih.gov/entrez/...ve&db=pubmed&dopt=Abstract&list_uids=12602850 - found that the lethal levels of nitrate in the species Catla catla were around 1500ppm - granted, this was for death in 24 hours, but it certainly throws a question mark over the idea that 60ppm is actually potentially lethal over any period of time.

This isn't to say it isn't harmful, just that it won't kill the fish.

 

[LongTime]

Originally posted by Skippy
Aside from the fish load I have also found that from time to time the stock fo Cardinals many LFS get in stock just isn't that hardy and you end up getting some losses.

That is true, it is always better, if possible, to wait until the LFS has had their fish for at least a week before you take them home. I have a lot of cardinals and they all came home without any loss, but I only purchase them from one particular LFS.

 

[English Lion]

Well being as everyone else has been blaming bio load I thought I'd go something different - One of those last 6 tetras is a mean killing machine! It may look cute and small but when your back is turned it's off on a rampage!!

Or maybe it's just too much bio load?

 

[anonapersona]

Were those studies done with a sudden change in nitrates or a slow build up of nitrates? While I expect that slowly building nitrates can be tolerated to high values, a sudden increase in nitrates may create enough stress that other normally benign bacteria or parasites get out of balance and create disease.

I think it is sort of like being in a smoky room, particularly if you are the smoker. The room can get more and more dense with smoke, and you might not be bothered by it. But, if you just walk in from the fresh air, it might be quite intolerable.

Originally posted by Faramir
No, nitrates are not acutely toxic to the vast majority of fish even at levels well above what we're talking about here. It's important to keep the levels low, but mostly as a guage to what other chemicals are building up in the water. A few fish - Apistos, checkerboards and what have you are acutely sensitive to nitrates, but most are not. The harm done by nitrates is uncertain, but many fish live for years in water far worse than this.
...
This isn't to say it isn't harmful, just that it won't kill the fish.