Romet 30


For freshwater-reared salmonids (trout and salmon) and catfish.

About Romet® 30 

Romet® 30 is an antimicrobial powder containing sulfadimethoxine with an ormetoprim potentiator.  Romet® 30 works by interfering with the folic acid (a Vitamin B) synthesis pathway.  Romet® 30 is typically used to treat Furunculosis and ESC.

Romet® 30 causes no toxic problems in fish or humans, and tissue examinations revealed no changes in muscle, kidney or other critical organ samples as animals gain folic acid from a healthy diet.


Romet® 30 must be mixed in with the fish feed at the feed mill. Unfortunately feed mills are not always likely to mix Romet® 30 due to a convenience issue.


Romet® 30‘s withdrawal period can be as short as 3 days for catfish. (This means that with a 5-day treatment period and 3-day withdrawal period, a catfish treated with Romet® 30 can be slaughtered 8 days after the drug is initiated.)

Freshwater-reared salmonids (trout and salmon)
Freshwater-reared salmonids (trout and salmon) have a required 42-day withdrawal period from Romet® 30 before being slaughtered.  Withdraw time is dependent on water temperature.

*Compared to other drugs, Romet® 30 has a shorter depletion time in the body and is rapidly broken down in feces and aquatic sediments.

Use Directions

Preparation of medicated feeds

Establish the weight of fish to be treated and calculate the amount of feed needed per day according to fish size and water temperature. Calculate the amount of Romet® 30 required for medicating the feed at the rate of 16.7 g of Romet®30 per 100 kg (7.6 g of Romet® 30/100 lbs) of fish body weight per day.

Medication of feed before pelletizing or extruding

Thoroughly mix the calculated amount of Romet® 30 into the mash feed prior to pelletizing or extruding.  Refer to the dosage table below for registered levels of use.

Feed Intake of Fish as Percent (%) of Body Weight

Feed Intake of Fish as
Percent(%) of Body Weight
Pounds of Romet® 30
per Ton of Feed
1.0% 33.30
2.0% 16.70
3.0% 11.10
4.0% 8.33
5.0% 6.66
6.0% 5.55

Medication feed after pelletizing

Prepare a liquid slurry by suspending Romet® 30 in edible vegetable oil or a 5% gelatin solution. Coat the pelleted fish feed with the slurry, which should be constantly agitated to ensure uniform suspension of the Romet® 30 during addition. As a general rule, 10 gallons of slurry is required to coat 2000 lb (1T) of pellets. The coated pellets should be allowed to air dry prior to bagging. Rebag and store under proper feed storage conditions.

Caution: Federal law restricts medicated feed containing this veterinary feed directive (VFD) drug to use by or on the order of a licensed veterinarian.
romet 30 bag

At a Glance

Species: fresh water reared trout, salmon and catfish
Category: therapeutics
Diseases: furunculosis and ESC


Romet® 30 Dosing Calculators

Romet® 30 Registered Dosage

Do NOT add commas eg. 500000

Romet® 30 Registered Dosage

Do NOT add commas eg. 500000

Get in Touch

Feel free to contact us with any questions about fish health, our products and services including vaccines and veterinary services.

Contact AquaTactics®


AquaTactics® Fish Health
12015 115th Ave NE, Suite 120
Kirkland, WA 98034 USA
Phone: 425-629-8099

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Contact Info

AquaTactics Fish Health®
12015 115th Ave NE, Suite 120
Kirkland, WA 98034 USA

Phone: (425)-629-8099