Slow, steady loss of fish

[Brhino]

I'm at my wit's end here, people.

In June of last year I increased the number of fish in my community tank to 15 fish, and since that time it's varied mostly in the 15-20 range. It varies because I lose fish, and I buy new fish. The species have been what's listed in my signature now... it's just the numbers that fluctuate.

All in all I've lost 18 fish in the 9 months since then. That's 2 per month on average, and that average has been pretty constant. I lost two that June, one more in august, 3 in October, five in november, one in december, one in february, and, unless an albino corydoras that I couldn't find today mysteriously shows up tomorrow, five this month in march. The shortest amount of time between deaths has been 3 days. Sometimes the dead fish is a new addition that has been with me for a matter of weeks. Sometimes it's one that's been with me for months or a year (which is saying something since I've only been doing this for just over a year).

Only one fish had any recognizable symptoms long enough before death for me to attempt to treat. The rest have given no indication whatsoever, or, at most, have stopped eating and become a bit lethargic. No dropsy, no ich, no fin rot, no flashing, no fungus, no injuries, no nothing.

I've never had detectable ammonia or nitrites. Never large amounts of nitrate. Never a pH change, or a sudden temperature change. Never missed a weekly 50% water change by more than a day. Never had a filter or a heater or a pump fail.

WHY DO MY FISH KEEP DYING LIKE THIS?

What am I missing? What am I doing wrong? What aren't I testing for?

What kills fish so slowly but steadily, never with a mass die-off, but never failing to claim a victim sooner or later?

I know I've basically asked this question before, but I don't know what else to do. It's starting to seriously effect my enthusiasm for the hobby at all. I understand deaths will happen, but there's been so many of these that I learn absolutely nothing from at all, which means I'm not taking any steps to prevent it from happening. People have said "poor quality stock", which I hate because it seems like such an excuse. Even if it's true, what am I supposed to do? My fish come from a LFS with a good reputation. Am I to find another store, shop there for 9 months, buying new fish, replacing losses, until I have enough data to tell if I'm doing any better with those fish?

I'm frustrated beyond belief. As always, any advice is greatly appreciated.

[Cliff]

sorry if I missed this, but do you always buy your fish from the same place?

Your LFS might have a good rep in the market, but what about their fish supplier ?

As I know you keep you parameters in line, that would be my guess. Things like inbreeding of stock resulting in weeker fish and health problems latter on in their lives might be leading to your situation.

Just my $0.02

[Goes to 11!]

sorry if I missed this, but do you always buy your fish from the same place?

+1

This is my first question also.

[Brhino]

Yeah, everything has come from my one LFS except for the betta (which came from... the grocery store? either that or petsmart/co. Wife bought it.), and the RCS, which I got from aquabid.

[Goes to 11!]

With consistantly so many casualties, You have to consider the fact that if everything is good on your end. It might be the sourcing of your stock.

It's very possible that they are not aware that the stock has an above average mortality rate - even under good conditions.

People have said "poor quality stock", which I hate because it seems like such an excuse. Even if it's true, what am I supposed to do? My fish come from a LFS with a good reputation. Am I to find another store, shop there for 9 months, buying new fish, replacing losses, until I have enough data to tell if I'm doing any better with those fish?

Don't kill the messenger but one definition of insanity is: 'Doing the same thing over & over and expecting different results.'

[Honey Badger 1]

do you immediately replace the dead fish or do you give it some time to see if more will die off. i know sometimes new ones die and sometimes older ones die, but i am interested to hear how quickly you replace the stock.
i'm wondering if it's maybe a parasite in the tank or possibly a dissolved oxygen issue.

[Brhino]

It varies. I buy fish in groups. Sometimes I buy a group not long after a fish has died, but sometimes there's a long gap. For example, there was a four month gap between July and November 2010 in which I added only 1 fish to the community tank. During that time I lost six fish. If it's a parasite, it's a very slow-spreading one.

My original community tank, which I considered "fully stocked", had two HoB filters and a bubble bar, so I find it unlikely that oxygenation could have been an issue in that tank. In the upgraded tank oxygenation may be an issue eventually (I plan to get a dissolved oxygen tester before I fully stock the tank), but as the tank is currently very lightly stocked I don't suspect I have an issue yet. In any case I have not seen any behaviors indicating potential oxygenation issues.

[Honey Badger 1]

sometimes its easier to find whats happening by ruling things out instead of looking for the actual cause.
some parasites do take time, some don't even kill the fish. so can't really rule that one out yet.
this tank is planted? is there a noticeable pattern to when the fish die, night, day, no discernible pattern. does the bubbler run all the time, so co2 isn't a problem?

[Brhino]

tank is planted, yes. Don't currently have a bubbler, but in the previous tank it did run all the time, yes.

Time of death is difficult to say. I don't typically actually witness the death. I do a headcount, often when I get home from work, and come up short. Then, I start searching for remains.

I was just looking at the tank again in the dark, and for a while I was convinced that I accounted for all five albino corydoras, including the one I figured to be dead. I can't be 100% certain, it's hard enough tracking them all with the lights on ("okay, there's 3 by the driftwood, and two under the wisteria, so that's all five. Wait... now there's only 2 under the driftwood, did one move to the wisteria?"). I certainly hope the fish is alive, but if so I've still lost four fish this month.

[mermaidwannabe]

You have RCS in the tank. How are they doing? Usually, invertebrates are more sensitive than fish, and if none of your RCS are dying off, you must have pretty good to excellent water conditions. I assume, of course, that you dechlorinate all new water you put into the tank.

I believe you ran a thread about glo-fish danios dying in significant numbers. These are genetically altered. They could be biologically unstable. And that could account for much of the loss. Anytime we mere mortals start messing around with genetics, we are in uncharted territory and the results can be less than desireable.

I also assume you don't overfeed and that the quality of food you give your fish is good, as well. I know you try to take very good care of your fish and your tanks.

So, like everyone else here, I think it's a safe bet that you either have poor quality stock, biologically unstable genetically altered fish, or some parasite or internal infection in your fish that manifests no outward symptoms.

I would have a talk with your LFS staff and tell them what has been going on. They might find issues with their suppliers. I'm sure if they're reputable, they don't want customers experiencing these kinds of losses so frequently. They'll probably want to get to the bottom of it as much as you do.

Sorry for all the losses. I know that when you've done all you can to maintain your fishes' good health and they still conk out without any obvious reason, it can be bewildering.

One other thing -- did you buy your tanks new or used? If used, could the previous owners have used soap in the tanks or some toxic substance gotten into them that may not have completely washed out when you cleaned them? If your tanks are new, there's no reason for anything to be in them that could harm fish. Still, sometimes things happen during the manufacturing process that cause trouble further down the line.

Just wondering if you might have wondered that, yourself ...

-- mermaidwannabe