Death of all goldfish over a week

[andy smart]

We are a secondary school, with a tank of coldwater fish in our lobby.
They have always been happy and healthy with no problems, over the
weekend of the 30th april we lost 4 of our goldfish and one of our
loaches - they were just floating on the surface on the tuesday morning.
The remaining fish were looking less lively than normal but were
interested in food. The shoal minnows (no idea of their real names) were
lively and as per normal. Over the course of the week we have since lost
all of our remaining goldfish and our other loach - they've not really
recovered and have been sitting on the bottom of the aquarium unless
it's feeding time when they come up.

We've cleaned the filter twice during the week and there is no obvious
foreign body in the water. The tank is large and has a lot of vegetation
- it's been a couple of months since we last added new fish, these came
from somewhere reputable and were the last to die.

Our first thought was that something had been put in the tank, either
via accident or malice, but I can't work out why these minnows would not
have been affected too. I've been though the websites for common fish
diseases and can't find anything which matches the symtoms. A couple
seem to have either lost their dorsal fins or were keeping them flat
against the body, but not all. Also if it was fin-rot it came on out of
nowhere and was very suddenly fatal.

Any ideas would be very welcome.

andy

[Geezer From The Freezer]

Andy,

How big was the tank in terms of litres or gallons, how many fish?
Did you ever change any of the water?
What were the ammonia, nitrite and nitrate levels. PH levels too?

How did you clean the filters?

[andy smart]

Geezer From The Freezer wrote:
> Andy,
>
> How big was the tank in terms of litres or gallons, how many fish?
> Did you ever change any of the water?
> What were the ammonia, nitrite and nitrate levels. PH levels too?
>
> How did you clean the filters?

Thanks for answering!

No idea what the literage is, but the dimensions are 120x40x35. It would
have contained ~ 8 'goldfish' of varying sizes and ages, 2 loaches, and
4 of these minnows. It's been up and running in it's present form since
around september, we moved it from another part of the school.

We replace evaporation using distilled water we make on site as required.

Don't know about nitrite and nitrate, but PH is 7 today.

We clean the filters by taking it apart and flushing it under hot water
till it is clean. It's one with two chambers of mesh with a central core
of filter wool (if that makes any sense) - it was last cleaned fully
around six weeks ago and was not particularly clogged after the sudden
death of fish over the weekend.

I had a good look at the fish which expired today, and apart from being
slightly ragged round the dorsal fin they do not have any visible
symptoms. What struck me was the suddeness of it, going from no visible
sign of trouble on friday to large numbers of dead by tuesday.

best wishes
andy

[secret squiddle]

"We clean the filters by taking it apart and flushing it under hot water
> till it is clean."

You should never 'clean' a filter with hot water. What I suspect you have
inadvertently done is killed all the friendly microbes the were living in
the filter, so the filter was sterile.

Filters work in two ways.

1. They mechanically remove solid dirt particles (or at least trap them)
2. They are home to thousands of micro organisms that eat the pollution from
the fish and render the fish waste harmless. Hence these bacteria are good
bacteria - and should be cared for accordingly.

In future only rinse the filter in tepid water (icy cold water can kill them
also, but not as much as hot water - which will eradicate 99% of the
microbes). Rinse in clean aquarium water is best to maintain the harmony of
the filter.

So without those friendly bacteria 'eating' the fish waste, the water would
have quickly become polluted - resulting in the death of all the fish.

For the same reason when restocking the tank (clean the tank and remove all
the water - you can use hot water to clean a fresh tank - just incase
there's anything bad from the stressed and dying fish, living in the water)
only introduce 1 or maybe 2 small fish to begin with. Only do this after the
tank has been up and running for at least 2 weeks (with the filter running).
The filter will take time to start working to maximum efficiency.

Also it's worth pointing out - that the filter should be running 24hrs a
day - to maintain the good bacteria in the filter. When you switch it off -
the bacteria can't feed and die.

**SS**

[secret squiddle]

"We clean the filters by taking it apart and flushing it under hot water
> till it is clean."

You should never 'clean' a filter with hot water. What I suspect you have
inadvertently done is killed all the friendly microbes the were living in
the filter, so the filter was sterile.

Filters work in two ways.

1. They mechanically remove solid dirt particles (or at least trap them)
2. They are home to thousands of micro organisms that eat the pollution from
the fish and render the fish waste harmless. Hence these bacteria are good
bacteria - and should be cared for accordingly.

In future only rinse the filter in tepid water (icy cold water can kill them
also, but not as much as hot water - which will eradicate 99% of the
microbes). Rinse in clean aquarium water is best to maintain the harmony of
the filter.

So without those friendly bacteria 'eating' the fish waste, the water would
have quickly become polluted - resulting in the death of all the fish.

For the same reason when restocking the tank (clean the tank and remove all
the water - you can use hot water to clean a fresh tank - just incase
there's anything bad from the stressed and dying fish, living in the water)
only introduce 1 or maybe 2 small fish to begin with. Only do this after the
tank has been up and running for at least 2 weeks (with the filter running).
The filter will take time to start working to maximum efficiency.

Also it's worth pointing out - that the filter should be running 24hrs a
day - to maintain the good bacteria in the filter. When you switch it off -
the bacteria can't feed and die.

**SS**

[andy smart]

secret squiddle wrote:
> "We clean the filters by taking it apart and flushing it under hot water
>
>>till it is clean."
>
>
> You should never 'clean' a filter with hot water. What I suspect you have
> inadvertently done is killed all the friendly microbes the were living in
> the filter, so the filter was sterile.
>
> Filters work in two ways.
>
> 1. They mechanically remove solid dirt particles (or at least trap them)
> 2. They are home to thousands of micro organisms that eat the pollution from
> the fish and render the fish waste harmless. Hence these bacteria are good
> bacteria - and should be cared for accordingly.
>
> In future only rinse the filter in tepid water (icy cold water can kill them
> also, but not as much as hot water - which will eradicate 99% of the
> microbes). Rinse in clean aquarium water is best to maintain the harmony of
> the filter.
>
> So without those friendly bacteria 'eating' the fish waste, the water would
> have quickly become polluted - resulting in the death of all the fish.
>
> For the same reason when restocking the tank (clean the tank and remove all
> the water - you can use hot water to clean a fresh tank - just incase
> there's anything bad from the stressed and dying fish, living in the water)
> only introduce 1 or maybe 2 small fish to begin with. Only do this after the
> tank has been up and running for at least 2 weeks (with the filter running).
> The filter will take time to start working to maximum efficiency.
>
> Also it's worth pointing out - that the filter should be running 24hrs a
> day - to maintain the good bacteria in the filter. When you switch it off -
> the bacteria can't feed and die.
>
> **SS**
>
>
Thanks for your input on this SS - we do run the filter 24/7 so we're
doing that right. I'm not sure where the beneificial bacteria would live
in our filter (the filter is very coarse hard plastic with a large mesh
size so there is nowhere for bacteria to thrive except in the core of
white filter 'wool') but I'll use tepid next time. Also remember that
the majority of fish died long before I cleaned the filter with hot
water, but before it was seriously clogged; any ideas as to what might
have caused this sudden initial death?

Could you offer some suggestions as to why one species of fish all
survived with no ill effects, while two others all died? If some species
are more 'tender' then perhaps we should avoid these?

Thanks again
andy

[Geezer From The Freezer]

Ok another point, just topping off evaporated water is not enough.
When you fish give off waste, this is released as ammonia,
your friendly bacteria in your filter media will turn this to nitrites
and other friendly bacteria in your filter turn nitrites to nitrates.
Nitrates need to be diluted out of the water, preferably before they
exceed 40ppm. When Nitrate gets high, it becomes more lethal the higher
it gets.

[Gail Futoran]

"andy smart" > wrote
[snip]
> Thanks for your input on this SS - we do run the filter 24/7 so we're
> doing that right. I'm not sure where the beneificial bacteria would live
> in our filter (the filter is very coarse hard plastic with a large mesh
> size so there is nowhere for bacteria to thrive except in the core of
> white filter 'wool') but I'll use tepid next time.

If your tap water contains chlorine or chloramines
any temperature will kill the useful bacteria. Filter
material (the "wool") should be rinsed in water
extracted from your aquarium during partial water
changes.

Some species can be more tolerant of poor water
conditions but that doesn't mean they're healthy. I
had a poorly maintained 10 gallon for awhile. The
only species that survived was the Cory cats.
But when I started to learn about nitrates etc., I
found my nitrates were in excess of 50, sometimes
to 100. So my poor Cories were barely surviving
while everything else died. (My tanks now are
well maintained.)

I didn't read earlier posts, so I'm not sure if
you've already done this, but the first step with
suspicious fish deaths is to test the heck out of
the water: pH, ammonia, nitrates, hardness.
You might even call your local water company to
find out if they changed anything recently with
respect to water treatment. A switch from chlorine
to chloramine, for example, can be deadly to
fish if you're only treating chlorine.

Sorry if you've already answered some of these
points. I had a computer glitch and missed
earlier posts.

Gail

[lgb]

In article >,
says...
> Thanks for your input on this SS - we do run the filter 24/7 so we're
> doing that right. I'm not sure where the beneificial bacteria would live
> in our filter (the filter is very coarse hard plastic with a large mesh
> size so there is nowhere for bacteria to thrive except in the core of
> white filter 'wool') but I'll use tepid next time.
>
The bacteria live on every surface in your tank and in your filter. I
rinse mine in the water I took from the tank for a water change.
Nothing else.

Pardon me if I'm wrong, but when you said in one post that you didn't
know what the nitrate level was, I got the impression you weren't an
aquarium expert :-).

Please do some reading on maintaining your aquarium. And DON'T trust
the local fish store. Some are OK, but a lot have underpaid and
ignorant employees while others are only interested in selling all they
can. Try your local library.

Good luck.

--
BNSF = Build Now, Seep Forever

[sophiefishstuff]

In message >,
Gail Futoran > writes
>"andy smart" > wrote
>[snip]
>> Thanks for your input on this SS - we do run the filter 24/7 so we're
>> doing that right. I'm not sure where the beneificial bacteria would live
>> in our filter (the filter is very coarse hard plastic with a large mesh
>> size so there is nowhere for bacteria to thrive except in the core of
>> white filter 'wool') but I'll use tepid next time.
>
>If your tap water contains chlorine or chloramines
>any temperature will kill the useful bacteria. Filter
>material (the "wool") should be rinsed in water
>extracted from your aquarium during partial water
>changes.
>
>Some species can be more tolerant of poor water
>conditions but that doesn't mean they're healthy. I
>had a poorly maintained 10 gallon for awhile. The
>only species that survived was the Cory cats.
>But when I started to learn about nitrates etc., I
>found my nitrates were in excess of 50, sometimes
>to 100. So my poor Cories were barely surviving
>while everything else died. (My tanks now are
>well maintained.)
>
>I didn't read earlier posts, so I'm not sure if
>you've already done this, but the first step with
>suspicious fish deaths is to test the heck out of
>the water: pH, ammonia, nitrates, hardness.
>You might even call your local water company to
>find out if they changed anything recently with
>respect to water treatment. A switch from chlorine
>to chloramine, for example, can be deadly to
>fish if you're only treating chlorine.


another really important point is that if you're only topping up rather
than changing water, an awful lot of gack (especially with goldfish who
produce a phenomenal amount of excrement) will build up in or on any
substrate you have, which will eventually lead to a fairly poisonous
environment. You need to get rid of this regularly; the easiest was is
with a so called "gravel vacuum" which is a really cheap & simple device
- a wide, rigid tube attached to a thin flexible piece of tubing - which
siphons gack and water out of your tank with each water change.
--
sophie

www.freewebs.com/fishstuff
(under construction. ish.)

[Tispe]

(snip)
"sophiefishstuff" > wrote in
message > >I didn't read >
>
> another really important point is that if you're only topping up rather
> than changing water, an awful lot of gack (especially with goldfish who
> produce a phenomenal amount of excrement) will build up in or on any
> substrate you have, which will eventually lead to a fairly poisonous
> environment. You need to get rid of this regularly; the easiest was is
> with a so called "gravel vacuum" which is a really cheap & simple device
> - a wide, rigid tube attached to a thin flexible piece of tubing - which
> siphons gack and water out of your tank with each water change.
> --
>

I had never heard the word "gack" until recently......is that the actual
"poop" or some other waste that develops from the "poop"?

Thanks,
Tispe

[andy smart]

>
> Pardon me if I'm wrong, but when you said in one post that you didn't
> know what the nitrate level was, I got the impression you weren't an
> aquarium expert :-).

No offence taken, the two of us who do this are the head science
tecnician and myself, school network manager!

[sophiefishstuff]

In message >, Tispe
> writes
>(snip)
>"sophiefishstuff" > wrote in
>message > >I didn't read >
>>
>> another really important point is that if you're only topping up rather
>> than changing water, an awful lot of gack (especially with goldfish who
>> produce a phenomenal amount of excrement) will build up in or on any
>> substrate you have, which will eventually lead to a fairly poisonous
>> environment. You need to get rid of this regularly; the easiest was is
>> with a so called "gravel vacuum" which is a really cheap & simple device
>> - a wide, rigid tube attached to a thin flexible piece of tubing - which
>> siphons gack and water out of your tank with each water change.
>> --
>>
>
>I had never heard the word "gack" until recently......is that the actual
>"poop" or some other waste that develops from the "poop"?

um.
it's a bit like "ick" or "yuck".
in a goldfish tank, it's a combination of old excrement and any old
food. and stuff.
--
sophie

www.freewebs.com/fishstuff
(under construction. ish.)

[Tom L. La Bron]

Andy,

You need to get some more test equipment. The school should be able to
purchase them relatively inexpensively, but you need a test kit that does
pH, KH, GH, nitrites and maybe nitrates. The nitrates are the least of any
problem in an aquarium eco-system. The thing that a lot of people forget is
that in the cycling processes of a tank they biobug also consume the
materials that makeup the carbonate hardness and also use the trace
elements. It is possible that since you are topping off the tank with
distilled water that you eco-system now has very soft water, which is
determental to Goldfish. You never mentioned the temps you were keeping the
tank at, but loaches and not cold water fish they come from the areas around
Borneo, Malaysia, etc. and temps very seldom get below 70 degrees in their
environment. In any event, the KH, GH and trace elements are important to
the tanks well being. Also I would like to point out that most loaches like
softer, more acid water, while Goldfish like a more alkaline (higher pH)
environment and harder water, your fish are really not compatible. The
loaches may live in your environment that you have created but that does not
mean that they like it or do well in it. Part of this problem, at the
moment, that I see is the fact that you are topping of this large tank with
distilled water which means no mineral content is in the water at all.

One other point, I figured that your dimensions were in centimeters since
you referenced the size of your tank in liters, but in any event, if it is
about a 40 gallon tank your environment is overstocked with fish.

Hope you get this cleared up. Tanks in schools can be so good for the
children.

Tom L.L.
----------------------------------------------------
"andy smart" > wrote in message
...
>
>>
>> Pardon me if I'm wrong, but when you said in one post that you didn't
>> know what the nitrate level was, I got the impression you weren't an
>> aquarium expert :-).
>
> No offence taken, the two of us who do this are the head science
> tecnician and myself, school network manager!

[andy smart]

Thanks for your input Tom

The loaches have been growing and thriving for about 3 years (they must
have quadrupled in size since we put them in) so I think they were happy
there.

We're going to look into some more testing, and your point about
softening of the water was interesting too. Perhaps something to harden
the water wouldn't go amiss for us then? We've got a PH in there which
is just about neutral right now.

The thing which really perplexed us was the very sudden downhill slide
from all the damn fish being happy and healthy; they'd been together in
that tank for over six months, swimming and eating like there was no
tomorrow - we'd really like to know what caused it to deteriorate so fast.

My dimesions were in inches if I remember: that tank is WAY more than 40
gallons given the number of buckets it takes to fill it!

ta
andy

Tom L. La Bron wrote:
> Andy,
>
> You need to get some more test equipment. The school should be able to
> purchase them relatively inexpensively, but you need a test kit that does
> pH, KH, GH, nitrites and maybe nitrates. The nitrates are the least of any
> problem in an aquarium eco-system. The thing that a lot of people forget is
> that in the cycling processes of a tank they biobug also consume the
> materials that makeup the carbonate hardness and also use the trace
> elements. It is possible that since you are topping off the tank with
> distilled water that you eco-system now has very soft water, which is
> determental to Goldfish. You never mentioned the temps you were keeping the
> tank at, but loaches and not cold water fish they come from the areas around
> Borneo, Malaysia, etc. and temps very seldom get below 70 degrees in their
> environment. In any event, the KH, GH and trace elements are important to
> the tanks well being. Also I would like to point out that most loaches like
> softer, more acid water, while Goldfish like a more alkaline (higher pH)
> environment and harder water, your fish are really not compatible. The
> loaches may live in your environment that you have created but that does not
> mean that they like it or do well in it. Part of this problem, at the
> moment, that I see is the fact that you are topping of this large tank with
> distilled water which means no mineral content is in the water at all.
>
> One other point, I figured that your dimensions were in centimeters since
> you referenced the size of your tank in liters, but in any event, if it is
> about a 40 gallon tank your environment is overstocked with fish.
>
> Hope you get this cleared up. Tanks in schools can be so good for the
> children.
>
> Tom L.L.
> ----------------------------------------------------
> "andy smart" > wrote in message
> ...
>
>>>Pardon me if I'm wrong, but when you said in one post that you didn't
>>>know what the nitrate level was, I got the impression you weren't an
>>>aquarium expert :-).
>>
>>No offence taken, the two of us who do this are the head science
>>tecnician and myself, school network manager!
>
>
>

[NanK]

http://www.mu.edu/~buxtoni/puregold/disease/disease.htm

This is a great link for more detailed information. The "Dandy Orandas"
web site has very gorgeous and $$$$$ fish. If they don't know how to
care for goldfish, nobody does. The site will help you look at your
maintenance issues and discover what went wrong.

As a novice I've made every mistake in the books. Just like you, I had
a no-problems setup for over a year. Then I added one new ill fish and
the whole system collapsed! I lost all the goldfish, but the white
clouds survived.

Understanding how goldies pollute their environment and knowing what to
do about it will make a huge difference.

Good luck.

nan