Losing fish...any ideas appreciated

Hi All,
This is really a continuation from the Sick Mollie in my son's tank and
subsequent loss of two Mollies last weekend. I did my normal check this
morning and now one of the Rosy Barbs is on her way out. Checked the water
pH 8 (normal for our tanks), 0 Ammonia and Nitrites and Nitrates are at 5.

No new fish added for months. Tank has been running since last August.

Tank is around 15UK galls. Current occupants are 1 mollie and 4 Rosy Barbs
(around 10 inches of fish maximum). Plenty of plants. Water changes are
weekly 20-30%. We've had very few problems with this tank until now.

I just can't figure out what is going on here or what to do next. If the
remaining Rosy Barbs would be OK with Gouramis I suppose I could move them
and then strip down the tank - this is the only thing I can think of for
now. But I hesitate because I don't want to risk infecting any of the other
fish in the other tanks.

Does anyone have any clues as to what might be happening or what I can do
next to keep the remaining fish?

Thanks
Gill

Thusly "Gill Passman" gillspamattaylorpassmanspam.co.uk Spake Unto
All:

Does anyone have any clues as to what might be happening or what I can do
next to keep the remaining fish?

What are the symptoms of the fish?

"Mean_Chlorine" wrote in message
...
Thusly "Gill Passman" gillspamattaylorpassmanspam.co.uk Spake Unto
All:

Does anyone have any clues as to what might be happening or what I can do
next to keep the remaining fish?

What are the symptoms of the fish?

They are absolutely fine until it happens. Swimming around happily and
feeding well - last night everyone was absolutely normal. No sign of any
bloating or distress or any marks on them at all. Then I just find them at
the bottom of the tank hardly moving and then they die. Gill movement is
normal and as I said there is no sign of any fungal infection or injury....

Gill

"Gill Passman" gillspamattaylorpassmanspam.co.uk wrote in message
.. .

They are absolutely fine until it happens. Swimming around happily
and
feeding well - last night everyone was absolutely normal. No sign
of any
bloating or distress or any marks on them at all. Then I just find
them at
the bottom of the tank hardly moving and then they die. Gill
movement is
normal and as I said there is no sign of any fungal infection or
injury....



Any foreign materials in tank? Recent addition of decorations?

"Billy" wrote in message
...


"Gill Passman" gillspamattaylorpassmanspam.co.uk wrote in message
.. .

They are absolutely fine until it happens. Swimming around happily
and
feeding well - last night everyone was absolutely normal. No sign
of any
bloating or distress or any marks on them at all. Then I just find
them at
the bottom of the tank hardly moving and then they die. Gill
movement is
normal and as I said there is no sign of any fungal infection or
injury....



Any foreign materials in tank? Recent addition of decorations?


Nothing added since the Barbs in Jan/Feb....also nothing taken out (apart
from the dead fish). No new decorations or even plants. Very small ammonia
spike (lowest reading) about 9 days ago along with a slightly higher pH
reading (which I'm not convinced I read properly). Rectified all of this and
have not had any suspect readings since a week ago last saturday but lost
another Mollie shortly after. No difference in how I treat the water -
follow the same routine on all of the tanks and there is no problem in any
of the others.

The only thing that I have done differently, a couple of weeks ago, was to
use a magnetic algae scraper. Haven't used it again as the fish kept trying
to get between it and the glass so I decided it was too risky to use it in
the tank.

It it is not disease or agression, I can only think that there is something
toxic in the water that I don't test for. But if that is the case I would
have expected them all to be carried off at once or at least within a few
days but this has not happened.





Test Kit is the same one I use on all the tanks and know to be accurate.

Gill Passman wrote:
"Billy" wrote in message
...


"Gill Passman" gillspamattaylorpassmanspam.co.uk wrote in message
...

They are absolutely fine until it happens. Swimming around happily
and
feeding well - last night everyone was absolutely normal. No sign
of any
bloating or distress or any marks on them at all. Then I just find
them at
the bottom of the tank hardly moving and then they die. Gill
movement is
normal and as I said there is no sign of any fungal infection or
injury....



Any foreign materials in tank? Recent addition of decorations?



Nothing added since the Barbs in Jan/Feb....also nothing taken out (apart
from the dead fish). No new decorations or even plants. Very small ammonia
spike (lowest reading) about 9 days ago along with a slightly higher pH
reading (which I'm not convinced I read properly). Rectified all of this and
have not had any suspect readings since a week ago last saturday but lost
another Mollie shortly after. No difference in how I treat the water -
follow the same routine on all of the tanks and there is no problem in any
of the others.

The only thing that I have done differently, a couple of weeks ago, was to
use a magnetic algae scraper. Haven't used it again as the fish kept trying
to get between it and the glass so I decided it was too risky to use it in
the tank.

It it is not disease or agression, I can only think that there is something
toxic in the water that I don't test for. But if that is the case I would
have expected them all to be carried off at once or at least within a few
days but this has not happened.





Test Kit is the same one I use on all the tanks and know to be accurate.



Usually, bacterial disease overwhelm fish quickly as you're seeing.
Parasites take longer. I would start feeding an antibacterial food, if
you can find one. You also might remove your biofilter media, treat the
tank with 2 ppm potassium permanganate for four hours (there should be
instructions on the bottle for amount), add dechlorinator - the
permanganate should change from pink/purple to brown, and then put the
filter media back. This will reduce both bacterial and parasitic
populations in the tank.

--
Elaine T __
http://eethomp.com/fish.html '__
rec.aquaria.* FAQ http://faq.thekrib.com

Gill Passman wrote:

Nothing added since the Barbs in Jan/Feb....also nothing taken out (apart
from the dead fish). No new decorations or even plants. Very small ammonia
spike (lowest reading) about 9 days ago along with a slightly higher pH
reading (which I'm not convinced I read properly). Rectified all of this and
have not had any suspect readings since a week ago last saturday but lost
another Mollie shortly after. No difference in how I treat the water -
follow the same routine on all of the tanks and there is no problem in any
of the others.

The only thing that I have done differently, a couple of weeks ago, was to
use a magnetic algae scraper. Haven't used it again as the fish kept trying
to get between it and the glass so I decided it was too risky to use it in
the tank.

It it is not disease or agression, I can only think that there is something
toxic in the water that I don't test for. But if that is the case I would
have expected them all to be carried off at once or at least within a few
days but this has not happened.

Here in Canada tanks may get quite warm at this time of year, from the
spring-summer temperature plus the heat of the lights, filter pump etc.
If that's the case you can open the tank lid a bit to let air flow and
cool things down; unplugging the heater can help, too.

When the water quality is suspected as in this case, I think it's ok to
do daily water changes of 30% - 50% for a few days. That will
effectively change most of the water in the tank.

Steve

Thusly "Gill Passman" gillspamattaylorpassmanspam.co.uk Spake Unto
All:

What are the symptoms of the fish?

They are absolutely fine until it happens. Swimming around happily and
feeding well - last night everyone was absolutely normal. No sign of any
bloating or distress or any marks on them at all. Then I just find them at
the bottom of the tank hardly moving and then they die.

They always die during the night?

"Mean_Chlorine" wrote in message
...
Thusly "Gill Passman" gillspamattaylorpassmanspam.co.uk Spake Unto
All:

What are the symptoms of the fish?

They are absolutely fine until it happens. Swimming around happily and
feeding well - last night everyone was absolutely normal. No sign of any
bloating or distress or any marks on them at all. Then I just find them
at
the bottom of the tank hardly moving and then they die.

They always die during the night?


They always get ill during the night....they die later either in the next
day or the following day/night

Thusly "Gill Passman" gillspamattaylorpassmanspam.co.uk Spake Unto
All:

They always die during the night?

They always get ill during the night....they die later either in the next
day or the following day/night

OK, that narrows it down a bit.

Two obvious alternatives are oxygen depletion and attacks by other
animals, e.g. some catfish, some crayfish... I had otocinclus which
attacked and killed fish during the night some while back, for
instance, and oxygen levels drop during the night.

However, you've listed your fish, and you've not got any fish which
should be capable of attacking other fish, and fish recover quickly
from oxygen shortage.

The main remaining possibility I can think of is flexibacter disease.
It is extremely virulent, and may kill fish so quickly that they never
develop any symptoms. The most resistant fish will, however,
eventually develop symptoms: white fungus-like growths, and ulcers on
their bodies, often around the mouth.

But until you see any symptoms, flexibacter disease is just a wild
guess based on the absence of evidence.