fungus in tank system

Peter Cattin p.cattin at auckland.ac.nz
Wed Dec 11 15:59:52 EST 2002


Dear Christina,

Your bleach should sort it out but the risk of making the 
polycarbonate tanks brittle and the worse risk of leaving behind a 
residual chlorine would push me towards hot water.  The chlorine 
will take out the spore stages though - just rinse well.  We use a 
dishwasher with a 3 minute cycle at 90 degrees C.  It sounds like 
you are heading in the right direction, just replace the 10-15% 
weekly not daily unless this is just a temporary measure to help 
remove the fungus.  

Feeding dry feed is the hardest part of zf management as it is so 
easy to overfeed which is one of the reasons live feed is so good.  

Are you feeding live Artemia/brine shrimp?  If you are, just feed 
brine shrimp once or twice a day for a few weeks and cut the dry 
feed out altogether.  If you aren't feeding Artemia, perhaps you 
should as it will greatly improve the health of the fish and won't 
contribute to the fungus problem.  

Try the above and if still no joy, come back to me and we can plan 
a hit with methylene blue.  

A powdered feed should be about 250 microns for adults and 
should float as zf are surface feeders.  

I thought it must be an AHAB system.

Regards,

Peter Cattin

Christina Quasarano wrote:

> Dear Peter,
>    We are using an AHAB system in our lab.  I have recently started
>    to feed
> the fish less to avoid the extra food fueling the fungal growth. 
> What I have been doing with the tanks that are infect is placing the
> fish in fresh tanks and bleaching the dirty tank with a ~5% solution
> for about an 30-60 minutes, then letting fresh deionized water rinse
> it out for a while.  Do you think that the hot water will be more
> effective?  I do replace 10-15% of the system water everyday, but
> still the fungus persists.  I am leaning towards overfeeding as the
> cause.  Thank you for your help.
>
> Sincerely, Christina Quasaranp
>
> Quoting Peter Cattin <p.cattin at auckland.ac.nz>:
>
> > Dear Christina,
> >
> > The problem of fungus is certainly one of water management and is
> > more than simply the ammonia.   You will have great difficulty
> > trying to "starve" the fungus out.  Your best bet is to remove the
> > offending tanks and put the fish into fresh ones.  Take the fungus
> > ridden tanks and wash them in water as hot  as the tanks can
> > stand.  If the fungus is in other parts of the system, try to
> > remove
> >
> > these parts and wash them also.  Get rid of the fungus physically
> > not chemically by attempting to starve them.
> >
> > But the main problem will be very high organic loading in the
> > water
> >
> > and probably uneaten feed left in the tanks for too long. 
> > Remember
> >
> > to replace 10% of the water every week and don't over feed.  It is
> > very easy to keep throwing feed at the fish but it doesn't do them
> > any good.  Just feed enough for the fish to eat in 1-2 minutes.
> > Vary the amount of feed with the number of fish in the tank.  Use
> > the correct feed and I can help you with that if you want.  Don't
> > kill them with kindness.  Remove any uneaten feed at least once a
> > week.  Better to feed too little than too much.
> >
> > I would be interested to know whose fish system it is that you are
> > using so I can better understand the nature of the problem with
> > the
> >
> > baffle filter ?
> >
> > Please let me know how it goes.
> >
> >
> > Sincerely,
> > Peter Cattin
> > --
> > Peter Cattin PhD
> > Department of Molecular Medicine & Pathology
> > Faculty of Medical and Health Sciences
> > The University of Auckland
> > Park Road, Grafton, Auckland.
> > Private Bag 92019, Auckland,
> > New Zealand
> >
> > Tel: +64-9-373-7599 xtn. 86373 or 87719
> > Fax: +64-9-373-7492
> >
> > Christina Quasarano wrote:
> >
> > > I am having a big problem with fungus in the tanks system I use.
> > I
> > > have shut off the unoccupied tanks to avoid contamination in
> > them.
> > > The problem exists in the tanks with the fish.  There is growth
> > > behind the plates in the back of the tank.  These plates are
> > > designed to keep the fish from flowing out with the water, but
> > allow
> > > waste etc to flow out underneath it.  The growth does seem to
> > > focus/accumulate around the area at the back of the tank where
> > the
> > > waste and dirty water flow under the plate. It is white in color
> > and
> > > appears in siphonous clumps when observed under a dissecting
> > > microscope. I have heard that methylene blue can be used to
> > > eliminate the fungus.  I am unsure of the concentration to use
> > and
> > > the side effects of this (both good and bad, other than
> > eliminating
> > > the fungus). If anyone has any suggestions or ideas, they would
> > be
> > > greatly appreciated!  thank you!
> > >
> > > Sincerely, Christina Quasarano
> > >
> > > ***************************************
> > > Christina Quasarano
> > > Research Assistant,
> > > Chemical Hygiene Officer
> > > Department of Anatomy and Neurobiology
> > > Phone # (617)638-4187
> >
> >
> >
>
> ***************************************
> Christina Quasarano
> Research Assistant,
> Chemical Hygiene Officer
> Department of Anatomy and Neurobiology
> Phone # (617)638-4187

--
Peter Cattin PhD
Department of Molecular Medicine & Pathology
Faculty of Medical and Health Sciences
The University of Auckland
Park Road, Grafton, Auckland.
Private Bag 92019, Auckland,
New Zealand

Tel: +64-9-373-7599 xtn. 86373 or 87719
Fax: +64-9-373-7492


---
------- End of forwarded message -------





More information about the Zbrafish mailing list