Acropora Red Bug Milbemycin Treatment Calculator

About the Treatment

Acropora Red Bugs (Tegastes acroporanus) are a common pest in Small Polyp Scleractinian (SPS) reef aquariums.  While they are nuisance and may slowly decimate Acropora colonies, there is a successful treatment method that uses Milbemycin Oxime which is a common treatment for dog heart worms.  This treatment protocol was developed by Dustin Dortin from ORA and we recommend his described regimen as it has proven effective at combating these pests.

NOTE: This treatment is highly dangerous to a large number of crustacean species.  If you follow this routine you understand that you will potentially kill acropora crabs, hermit crabs, mithrax crabs, arthropods, copepods and other critters.  It is possible that your shrimp may live but it is really not guaranteed.  You will likely have a small ammonia spike if you have a large number of critters living on your live rock and live sand.  This website takes no responsibility for you following these instructions and you assume all consequences and results of this treatment.


The Treatment

Contact your local veterinarian to obtain the pills.  The brand name that is found in the USA was previously Interceptor but there has been a recent change in availability and you will need to ask your vet for the latest form.  The pills are designed for dogs to take orally so they typically include beef flavoring which does not appear to cause problems in aquariums with high water movement and adequate aeration.  The use of a protein skimmer as well as constant water movement is recommended when adding the mixture to your aquarium.

When you have a source for the Milbemycin pills you will have to determine which strength you have.  Small pills were designed for small dogs obviously so the size and density of the pills will vary.

The most important thing about this calculation is that we are interested in the milligrams of Milbemycin, not the mg of the pill itself.  So the calculator below will tell you the percentage of a pill that is needed for a single treatment.

It is recommended that you complete three treatments, each one week apart.  Following each treatment you are to watch for signs of stress in your aquarium, and perform moderate water changes (10-25% after each treatment).

It is suspected that carbon filtration may capture the active compounds so during the treatment you should turn off your activated carbon reactors and run new carbon after the treatment.

Calculator Instructions

  1.  Enter the size of your tank in US gallons
  2. Select the “color” of pill you have.  The package will have one of five colors and the color indicates the strength of the pill.  Typically the pill sizes are 3mg, 5.5mg, 11mg, and 23mg.
  3. The percentage reported by the calculator is the percentage of that particular color pill.  Example: 500% means 5 pills, .75 means three quarters of a pill, etc.  The Milbemycin at this dosage allows you to cut the pill by hand, but pay attention and do your best to cut the proper proportions.  If possible, find the proper color/concentration pills to make your treatment regimen easy.
  4. Crush the pill into powder with a mortar/pestle or a pill crusher.  You can get a decent crusher for $5 at any pharmacy.
  5. Mix the powder with RODI water.  A cup of water should suffice for most common aquarium sizes.  If your tank is extremely large you should probably be mixing it with a gallon or two of water and adding it to the aquarium slowly.  Otherwise mix the powder until it is completely dissolved and immediately add to a high flow section of the aquarium.  There will be some large white particles that are at the bottom of your mixing vessel.  These are the actual milbemycin, so if it is not gradually dissolving into the RODI water then pour the liquid into the tank and add more RODI to continue to dissolve the smallest bits of the original pill.
  6. Your shrimp and crabs will start acting funny and getting very slow.  Again, as indicated before, this process will typically kill off beneficial

Treatment Calculator

Select Pill
Pill Data
Pill Name: N/A High Dosage: N/A Low Dosage: N/A
Water Volume in Gallons
Required Dosage N/A