When I first started learning about betta care, I kept running into words that made me scratch my head.
“What’s a flare stick?”
“Do I need to vacuum my gravel?”
“And wait – they breathe air?!”
I’d stop mid-article to Google them, only to end up rabbit-holing my way through Reddit, or wading deep into scientific papers.
This glossary is a beginner-friendly guide to the terms that stumped me. I’ve done the research, asked the questions, and pulled it all together in one place to make things easier for you.
Each definition is short and clear, with clickable links to help you explore more when you’re ready. I hope this helps you feel more confident and curious as you learn, whatever stage in your journey you may be at.
PS: If you run into a betta term that’s not here, let me know – I’m always learning too!
Acclimation
The process of gradually introducing your betta to new water conditions to prevent shock.
Air Stone
A small, porous stone that creates tiny bubbles to improve water circulation and oxygenation. Like a little underwater diffuser for your fish!
Algae Balls
Another name for marimo moss balls, which are actually a type of slow-growing algae that naturally grows into a ball shape and adds a touch of greenery. They’ve been known to live over 100 years in the right conditions!
Ammonia
A toxic compound produced by fish waste and decaying matter. Too much can be deadly, so ammonia control is a top priority in keeping your betta comfortable.
Ammonia Burn
Damage to a betta’s gills and fins caused by high ammonia levels. Signs include red, inflamed gills and struggling to breathe.
Anubias
A hardy, slow-growing aquarium plant that bettas love to rest on. Even beginners can keep it alive – it’s basically the indestructible houseplant of the fish world.
Aquarium Salt
A non-iodized salt used to help treat minor infections and improve gill function. (Not to be confused with marine, table, or Epsom salts – each one does something different!)
Aquascaping
The creative process of turning your tank into a tiny underwater garden. Think cozy jungle vibes or zen rockscape – whatever suits your betta’s aesthetic.
Baffled Filter
A DIY or store-bought modification to diffuse the current coming out of the filter, since bettas prefer calm water.
Betta Beads
Soft, biodegradable beads marketed to release beneficial bacteria into the water. A nice idea, but not a substitute for actual tank maintenance.
Betta Bulbs
Live plant bulbs (like Aponogeton) that grow into lush tank greenery. A mystery bag of potential beauty!
Betta Hammock
A small leaf-like rest station near the water’s surface. If you prefer real plants, try Broad Leaf Anubias or Dwarf Water Lettuce. Perfect for bettas who appreciate the finer things in life, like a mid-afternoon lounge.
Betta Pellets
The go-to staple food for bettas, designed to provide balanced nutrition. Look for high protein content and avoid fillers like wheat or soy. Add treats of frozen bloodworms or brine shrimp to round out their diet.
Biological Filtration
Good bacteria live on your filter and in your gravel, quietly turning toxic waste into safer stuff. They’re the unsung heroes of your tank – doing the dirty work so you don’t have to.
Bloodworms
A protein-packed treat for bettas. These tiny red larvae are basically their guilty pleasure. Just don’t overdo it.
BPM (Bubbles Per Minute)
A way to measure how much air a bubbler or air stone is producing. Too many can ruffle a betta’s fins, so gentle is usually best.
Breeding Pair
A male and female betta chosen for breeding. It’s not a casual date – it takes planning, prep, and a watchful eye to avoid heartbreak (and injury).
Breeding Stripes
Pale, vertical stripes on a female betta that indicate she’s ready to mate.
Breeding Tank
A separate tank set up specifically for betta breeding, with calm water, no substrate, and hiding spots for the female.
Brine Shrimp
Tiny aquatic crustaceans that make an excellent live food for bettas. It’s fast food with a nutritional upgrade.
Bubble Nest
A cluster of bubbles created by male bettas on the water surface as a cozy nursery for potential eggs. It’s a good sign that he’s happy and healthy!
Bubbler
A device that adds oxygen to the water by creating bubbles (also known as an air pump). It’s not always necessary for bettas, who breathe from the surface, and it can make them stressed.
Bug Bites
A popular fish food made with insect protein, mimicking a betta’s natural diet.
Clamped Fins
When a betta keeps its fins tight against its body, often a sign of stress or illness.
Columnaris
A bacterial infection that looks like fuzzy white patches on the fish. It’s fast-acting, so early treatment is crucial.
Conditioning Bettas
The process of feeding high-protein foods and optimizing water conditions before breeding.
Cycling A Tank
The process of building up beneficial bacteria in your tank before adding fish. It lays the foundation for safe, stable water – kind of like seasoning a cast iron pan before cooking.
Daphnia
Tiny freshwater crustaceans, also known as “water fleas,” that make a great snack for bettas.
Detritus Worms
Small worms that live in aquarium substrate, often appearing when waste builds up. Not dangerous, but a sign your tank needs cleaning.
Diamond Eye
A condition in some bettas (especially dragon scale varieties) where excess scaling covers part of their eye, reducing vision.
Driftwood
Natural wood used in aquariums to create hiding spots and release tannins, which bettas love. Curing wood found in nature can take several months, or you can buy wood already prepared for an aquarium.
Dropsy
A serious symptom involving a bloated body and “pineconing” scales. It can be caused by a bacterial infection, virus, or parasite, and is usually fatal unless you can catch it early and treat it.
Egg Bound
When a female betta has eggs but doesn’t lay them, which can lead to infection. It can sometimes resolve on its own, but in extreme cases, it requires intervention.
Egg Spot
A small white dot on a female betta, indicating where she releases eggs.
Fancy Betta
A general term used by hobbyists and retailers to describe bettas with unique colors, patterns, or fin shapes. Not a scientific category – more like calling a dress “extra.” Think crowns, halfmoons, koi patterns, and other eye-catching traits.
Feeding Ring
A floating ring that keeps food in one place on the water, preventing it from scattering across the tank.
Filter Baffle
A DIY or store-bought modification to diffuse the current coming out of the filter, since bettas prefer calm water.
Fin Nipping
When a betta (or tank mate) bites fins, leading to frayed edges. A common issue with aggressive or stressed fish.
Fin Rot
A bacterial or fungal infection that causes fins to deteriorate. You can treat it with clean water and medication.
Fishless/Fish-In Cycling
Two ways to establish the nitrogen cycle that will keep your water clean. Fishless is far safer, whereas fish-in requires careful ammonia monitoring.
Flare Stick
A small toy used to encourage flaring, often shaped like a rival fish. Great for short bursts of exercise, but don’t overdo it – aim for a gym selfie sesh, not a fight club.
Flaring
When a betta spreads its fins and gill covers wide, usually as a display of dominance or excitement.
Flashing
Quick, darting movements where a betta rubs against objects to scratch an itch, often due to parasites.
Floating Plants
Plants whose roots don’t need to be planted in the substrate, so they drift at the water’s surface providing shade and hiding spots. Some easy ones for beginners are Salvinia, Brazilian Pennywort, Water Sprite, and Anacharis.
Fry
Baby fish! Tiny, delicate, and in need of special care. Betta fish are considered fry until around 8 or 9 weeks old.
GH (General Hardness)
A measure of dissolved minerals in the water, primarily calcium and magnesium ions. It’s important for fish health because it’s closely related to pH levels.
Gill Fluke
A tiny parasitic worm that irritates a betta’s gills, causing heavy breathing and flashing.
Glass Surfing
When a betta repeatedly swims along the tank walls, often due to stress or boredom.
Gravel Vacuum
A siphon tool used to clean debris from the substrate. Many betta owners vacuum weekly with their water change.
Hard/Soft Water
Water hardness depends on mineral content. Bettas prefer soft to moderately hard water.
Heat Pack
A warming pack used during shipping to keep bettas cozy.
Hole In The Head Disease
A condition causing pitted lesions on a fish’s head, linked to poor water quality and diet.
Ich
A common parasite that appears as tiny white spots, like your betta is sprinkled with salt. It can be treated with medication, high quality food, and careful attention to water parameters.
Indian Almond Leaf
A natural remedy that releases tannins, helping reduce stress and prevent infections.
Java Moss
A hardy, beginner-friendly plant that bettas love to explore.
KH (Carbonate Hardness)
Measures the amount of carbonates and bicarbonates in the water. Low KH means the pH level will change easily; high KH means pH will be harder to change.
Labyrinth Organ
The special organ that bettas use to breathe air from the surface.
LFS (Local Fish Store)
Your go-to place for fishkeeping supplies, often with better care standards than big-box pet stores.
Live Food
Fresh or frozen critters like brine shrimp, daphnia, and worms. Bettas love the movement – it taps into their inner hunter and adds variety to their diet.
Live Plants
The real MVPs of a healthy tank. They oxygenate the water, soak up excess nutrients, and make everything look lush. Plus, your betta will appreciate the natural scenery.
Marimo Moss Ball
A type of slow-growing algae that naturally grows into a ball shape and adds a touch of greenery. They’ve been known to live over 100 years in the right conditions!
Microworms
Tiny live food, perfect for feeding baby bettas (fry). Like baby formula but for fish.
Morphs
Different color, pattern, and tail variations used to classify bettas.
Mouth Brooder
Wild betta species where the male carries fertilized eggs in his mouth until they hatch. Males from other betta species build bubble nests on the surface. It’s thought that mouth brooding evolved as a mechanism to keep the eggs safe in stronger currents.
Nitrate
A byproduct of the nitrogen cycle that builds up over time. It’s less toxic than ammonia or nitrite, but high levels (over 20–40ppm) can stress your fish. Regular water changes help keep it in check.
Nitrite
A harmful chemical formed during the breakdown of ammonia. It’s highly toxic to fish, so you want this at 0ppm. (Tip: “nitrite” with an “i” = immediate problem.)
Nitrogen Cycle
The biological process that turns toxic fish waste into less harmful compounds, thanks to helpful bacteria. It’s essential to understand before adding any fish – your betta’s life literally depends on it.
pH
A measure of how acidic or alkaline the water is. Bettas prefer slightly acidic to neutral water (6.5-7.5).
Pineconing
When a betta’s scales stick out like a pinecone, usually a death sentence caused by internal organ failure.
Planted Tank
An aquarium designed with live plants, creating a natural and enriching environment for bettas.
Popeye
A condition where a fish’s eyes swell abnormally due to infection or poor water quality.
Quarantine Tank
A separate tank used to isolate sick or new fish before introducing them to the main tank.
RO Water (Reverse Osmosis)
Purified water stripped of minerals. It needs to be re-mineralized before use in a betta tank.
Siamese Fighting Fish
The official name for bettas, referring to their aggressive nature and origins in Thailand.
Silk Plants
The next best thing to live plants. Unlike plastic ones, these won’t shred your betta’s delicate fins.
Sorority Tank
A tank with multiple female bettas, usually raised together. Requires careful management and close supervision from an experienced fish-keeper since bettas can be territorial!
Special Buy Betta (Petsmart)
A label for bettas that don’t fit the standard categories. Sometimes a hidden gem, sometimes a genetic mystery.
Split Tank
A tank with a divider that can house two bettas separately, to prevent fights. Bear in mind that seeing another betta can be stressful, and they still need at least 5 gallons each.
Sponge Filter
A gentle, air-driven filter that provides both mechanical and biological filtration. Great for bettas!
Stress Stripes
Horizontal stripes that appear on a betta when they’re anxious or scared. Think of it as their version of a furrowed brow – a visual cue that something’s not right.
Substrate
The material lining the bottom of the tank, like gravel or sand. Helps anchor plants and replicates a betta’s natural environment.
Swim Bladder Disease
A condition affecting a betta’s buoyancy, making it hard to swim properly. Symptoms include floating awkwardly, sinking, or swimming sideways like a malfunctioning submarine. Most fish can recover fully with prompt treatment.
Tank Divider
A barrier that lets two bettas share a tank without fighting. Bear in mind that seeing another betta can be stressful, and they still need at least 5 gallons each.
Tank Mates
Other fish or aquatic creatures that can safely coexist with bettas – though bettas can be picky roommates!
Tannins
Natural compounds released by driftwood or Indian almond leaves that tint the water brown and provide antibacterial benefits.
Trio Tank
tank divided into three sections, typically used for breeding setups or housing multiple bettas.
Velvet Disease
A parasite that gives bettas a gold-dust-like shimmer. Curable if caught early.
Vertical Death Hang
An unsettling posture where a betta floats upright, motionless, head-up. A grim sign of severe illness.
Water Changes
The regular practice of replacing a percentage of the old water with fresh, clean water to keep bettas healthy.
Water Conditioner
A must-have additive that removes chlorine and harmful chemicals from tap water.
Water Parameters
The key water conditions like temperature, pH, and ammonia levels that affect betta health. You can use an aquarium testing kit to keep track of them.
Wild Betta/Wild-Type Betta
The betta species that exist in nature, typically with less flashy colors and more chill attitudes than their domesticated counterparts.