[Zbrafish] Re: seasonal mortality?

[Jocelyn]

Off list I received three emails indicating a shared experience of
increased nursery mortality in fall.

More about our parameters:
+ we have an RO/DI water source.
+ we have consistent personnel year round (ie full time staff, no
student workers).
+ we feed powdered AP diet and raise brine shrimp for our nursery fish
(no paramecia, rotifers, etc ).
+ another zebrafish facility in the same building reported anecdotally
about similar problems at the same time.

Will seasonal changes in city water persist through a RO/DI system?
I'm coming to think so?

thanks for your feedback.
As always, its been interesting.