Parasite-S (Formalin)

Parasite-S (formalin) is available in 55 gallon drums, 275 gallon totes and 4 x 1 gallon cases.

Contact us for pricing and assistance at 800-283-5292 or

Parasite-S (Formalin)


PARASITE-S (formalin) is an FDA approved parasiticide for the control of external Protozoa and Monogenetic Trematodes on all finfish, and external Protozoa on penaeid shrimp (FDA NADA # 140-989).  It is also approved as a fungicide for all finfish eggs.  See the "Directions for use" link for approvals and directions for use.  

PARASITE-S (formalin) is manufactured in FDA approved and inspected production facilities and is FDA approved for use on fish as noted above.  The use of other grades of formaldehyde on fish may be in violation of FDA regulations as outlined in FDA Reminder to Aquaculture Producers Regarding Approved Formaldehyde.

Parasite-S (formalin) is available in 1 gallon jugs 55 gallon drums and 275 gallon totes.  Syndel has Parasite-S (formalin) warehoused in both Western and Eastern locations to allow for cost effective shipping throughout North America.  We have discounted shipping rates with most major freight companies and we can provide cost effective shipping quotes to locations throughout the United States.  In Canada, Parasite-S is available through Syndel Laboratories

PARASITE-S (formalin) is classified as a hazardous material and it must be shipped and handled according to DOT Hazardous Material regulations.  It is not sold on-line.  Please call our office for pricing information and delivered pricing quotes.  New users are encouraged to seek advice from a fish health professional prior to using this product.  Refer to the “Directions for Use”, and MSDS links for details on directions for use prior to treating fish of any life stage, as well as limitations and cautions for all uses.

COLD WEATHER NOTICE - Parasite-S is temperature sensitive and should not be allowed to reach temperatures below 40 degrees F. Regional weather conditions vary greatly and Syndel advises that all formalin users should to stock up on product prior to the cold weather season.  For more information, and to give us authorization to ship during questionable weather, please refer to our Cold Weather Authorization form.


The American Fisheries Society - Fish Culture Section's Working Group on Aquaculture Drugs, Chemicals, and Biologics (WGADCB) has published a Guide to Using Drugs, Biologics and Other Chemicals in Aquaculture.  WGADCB have also developed a Treatment Calculator to assist in the dosage calculations of certain products.

The Guide is provided as an Adobe PDF file and the Treatment Calculator is offered as a Microsoft Excel 2007 file.  Your computer must have installed either Microsoft Excel or any other program that will read and execute calculations of an Excel file.  The Guide and Treatment Calculator can be found by clicking the link below

Guide to Using Drugs, Biologics and Other Chemicals in Aquaculture

*Treatment Calculator (Excel 97-2003)

*Treatment Calculator (Excel 2010)

*Although the calculator has been checked for accuracy and can be a useful tool to aid in calculating treatment dosages, the end user is responsible for correctly applying any regulated compound in aquaculture