Welcome to the second episode of our Reef Tank Pest Control video series. Our focus for this video is going to be those pesky little flatworms, Red Planaria.

Red Planaria or sometimes called red flatworms are small, flat creatures, averaging about 1/8” in size and rust brown in color

They are more of a nuisance in your tank and typically will not pose an immediate threat to corals or other tank inhabitants, none the less they are quite common, and populations can quickly explode in your reef. When the population gets out of control, this is when the problems begin. They can irritate corals and consume detritus that could otherwise be available for more beneficial micro-fauna such as copepods. They can also release a strong toxin into your tank when they perish.

Planaria will get into your tank via rocks or coral frags, they feed on detritus and the population will typically be a good indication of your tank’s cleanliness. In systems with high nutrients and substantial waste, a larger population of these critters can be sustained to a point were just about every surface in the tank, corals included, will be covered in rust brown colored flatworms.

The biggest risk with flatworms is the toxin they release into your tank when they die. Some hobbyists have reported mass die offs of flatworms in an aquarium that led to a complete tank crash. For this reason, physical removal of the flatworm is crucial to a successful eradication.

Natural predators are effective against small populations of red planaria, Six Line and Leopard Wrasses are the most popular but also target mandarin dragonettes and the Blue Velvet Nudibranch have been reported to feed on Red Planaria.

Thankfully, chemical remedies are very effective against flatworms but you want to be careful. Dosing a product such as Salifert Flatworm Exit or Korallen-Zucht Flatworm Stop will kill all of the flatworms in your tank which will then release a harmful toxin.

To avoid poisoning your tank with this planaria toxin, you will first want to repeatedly siphon out all of the flatworms you possibly can. A 4-6 ft piece of airline tubing works great, you can easily attach a small micron filter media bag or filter sock to one end of the tubing to effectively trap the flatworms and not remove any tank water from your system. You will likely need to repeat the siphon process daily for a few days in a row to substantially drop the population.

After you have removed all visible signs of flatworms from your tank, go ahead and dose with the appropriate amount of chemical treatment. You will start to notice the flatworms die within about 10-30 minutes.

An immediate water exchange will be required after treatment and it is best to actively siphon out the flatworms as they die inside your tank. This way you can minimize the amount of toxin being released in your water column.

You will also want to run some carbon after the treatment to remove the residual chemical treatment and any planaria toxins from your water. Sometimes repeat dosage is necessary to completely rid your tank of planaria so be prepared to continue your siphoning and maybe even treat the tank again with a chemical.

If you are experiencing a frustrating pest in your reef, be sure to follow along with us here on youtube because we will be creating an entire series of videos with each episode focused on a different reef tank pest. You can also give our customer service team a call anytime for fast and friendly support.

Be sure to subscribe to our YouTube channel and follow along with us on social media to stay on top of all the latest Marine Depot news. I appreciate all of you for watching and until next time, take care and happy reefkeeping.

#flatworms #redplanaria #reefpests



WATCH PEST CONTROL VIDEO SERIES (episode 1 is about aiptasia!):