It is also sometimes known as mouth rot or mouth fungus. However, it is NOT a fungal infection. It is, in fact, a bacterial infection that can be external or internal. It can also be either chronic or acute. Why is it mistaken for a fungal infection? This is likely due to the presence of fungus-like lesions which can appear on your betta fish. Under most circumstances, you will want to dose 1 tablespoon of sea salt per gallon of aquarium water. At this dosage the salt will usually kill fungus, and may act as a general tonic for the fish. However, some species of fish, like cory catfish, can not tolerate salt in any amount. Others, like cichlids and tetras from soft acidic home waters From 2000 – 2008 there was very little online discussion about the use of garlic as a natural remedy for treating tropical fish. There were a few sporadic references to Seachems Garlic Guard, which is marketed as an Appetite and Flavor Enhancer for both freshwater and marine fish. For the first time, the Seachem product referenced garlic oil Low Oxygen Levels. The most obvious cause of a betta fish breathing heavily is a lack of dissolved oxygen in the water. Even though betta fish are labyrinth fish and can breathe oxygen from the air with their labyrinth organ, they also like to breathe a portion of their oxygen intake from the water. Addressing the health concerns of fish is somewhat of an art form, especially for Bettas with their distinct characteristics. This inspired me to create this guide. In it, I delve into 15 typical health issues Betta fish may face, along with thoroughly researched solutions for each. Let’s dive in. Also Read: Betta Fish Care Guide. 1. Fin Rot Body Fungus. Body fungus -- despite the name -- can infect the gills of a betta. The fungi that cause it belong to the related genera Saprolegnia and Achyla. This true fungal infection typically looks like whitish cottony growths. The strands may pick up colors from debris, giving them other colors. You can treat this infection with antifugal Although he is acting entirely normal, energetic, and with a regular (nice) appetite, my betta has had a persistent white spot next to his mouth. It has not gotten worse or better, just remained the same. It really doesn't seem to effect him at all, but it sure worries me. At first I suspected mouth fungus, and used API Bettafix for a full round. Betta Fish Diseases and Emergencies. Deadly cotton mouth?? 131 Views 4 Replies 4 Participants Last post by BettaStarter24, Jan 25, 2017. S. StayCee089 Discussion LZkuBL.