[Zbrafish] embryo contamination

[antiquemaniac47906 from yahoo.com]

> We are experiencing contamination inside the chorion of our zebrafish
embryos.  A 10% system water change occurs 3-4X per week and water
quality tests show normal ranges.  The
fertilized eggs are washed with .003% bleach within 20 minutes of
fertilization.  Our breeders are about 1 year old.  The embryo media
is changed
every 24 hours.
>
>
>  The contaminant appears as a cloudy white, flocculent mass which
increases over time until the embryo dies.  Does anybody have any
suggestions as
to how we may combat this issue.
>
>
>   Thanks for your help,
>
>  David Southern  - Jim Marrs Lab IUPUI
>
>  Don Ratcliffe     - Jim Marrs Lab IUPUI
>