Formalin Drip Treatment For Eggs
in Bell Jar Incubators
Disclaimer:
• This presentation is a formalin treatment example for eggs in
bell jar incubation systems. This example should be used as a
basic guideline and not meant to be specific to a farm or
hatchery. It is important to develop operational procedures that
relates to an individual farm or hatchery.
Calculating Constant Flow Treatments
• FDA approves 1000-2000 µL formalin concentration for
egg treatments in a flow through system
• DO NOT treat if fry are present or if eggs are close to
hatching.
Step 1. Determine Volume of Water
in Trough/Head Tank
• Why?
To make sure that at least one exchange of water happens in the
trough during the 15 minute drip treatment.
Head Tank Example:
Inflow = 5gpm
5gpm x 15min = 75gal water flow through in 15min
Trough Volume = 72in x 11in x 12in =9,504in3
231in3 in 1 gal so 9,504in3 / 231in3 =41.1gallons tank volume…
What does this mean?
Therefore, in 15 minutes, 75 gallons has flown through the head tank
(which we calculated is 41gallons in volume). This means the head tank
water has been exchanged at least once in 15 minutes.
Step 2. Calculate Amount of Formalin
• Amount of Formalin to add to inflowing water over the course of 15
minutes:
75 gallons (total water flow in 15 minutes) x
0.00378 g/gal (Correction Factor to accurately get treatment in ppm) x
1667ppm (Recommended Formalin Treatment) x
1 (100%) Active Formalin = 472.6ml of Formalin
Step 3. How to Disperse Treatment
over 15 minutes
To disperse treatment into head tank, the easiest way is to use a
chicken waterer and drill a hole in the outer rim.
What size hole to drill
to ensure 15 minute drip?
According to Introduction to Fish Health
Management , a 1/16th inch hole in a chicken
waterer delivers 946ml of
liquid in 15 minutes.
It is a good idea to verify and test
your chicken waterer to insure
15 minutes is the total time it takes to
disperse the volume above.
Simply use water to test this.
We calculated that we need 472.6ml formalin to drip out in 15 minutes to achieve
desired treatment.
946ml total volume needed – 472.6ml formalin= 473.4ml of water to add with
Formalin
Step 4. Add Treatment + Water
• Wear a chemical respirator
mask to add 472.6ml of
formalin treatment to a chicken
waterer.
• Now add in 473.4ml of water to
the chicken waterer to bring the
total volume up to 946ml of
total liquid in the waterer
(formalin + water)
It is a good idea to mark out on the
chicken waterer where the total
volume of 946 ml (formalin +
water) comes to on the jar.
This way, next time you need to
treat, you can simply measure out
the 473ml of Formalin to the jar,
then add enough water to reach
your mark.
Step 5. Treatment Placement
• Place chicken waterer to drip into
head tank and begin treatment.
Make sure it is stable and will not
tip over.
• Placement of drip should be
situated near inflowing water or
air diffuser so that the treatment is
well mixed in the head tank
before flowing to eggs.
• Be sure to monitor treatment.
• Proactively treat eggs every few
days or daily if fungus is
observed. This is also based on
individual hatchery protocols.
Questions or More Information…
Contact UWSP-NADF Outreach Specialist:
Emma Wiermaa
[email protected]
Resources & References
University of Wisconsin-Stevens Point
Northern Aquaculture Demonstration Facility
aquaculture.uwsp.edu
Introduction to Fish Health Management
United States Department of the Interior
Fish and Wildlife Service
Second Edition 1995
American Fisheries Society Fish Culture Section
Guide to Using Drugs, Biologics and other Chemicals in Aquaculture &
Treatment Calculator
http://fishculture.fisheries.org/working-group-on-aquaculture-drugs-chemicalsbiologics/wgadcb-resources-tools/guide-to-using-drugs-biologics-and-otherchemicals-in-aquaculture/