Betta Fish Rubbing Against Rocks, Plants, Glass & Filter

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Quite frequently, I noticed that my betta fish rubs against objects such as rocks and filters. At first, I ignored the phenomenon. I believed that it was merely playing and investigating its surroundings. However, as the issue progressed, I began to investigate other possible causes for rubbing among bettas.

Betta fish often rub against objects like rocks, glass, filters, and plants due to an underlying disease, such as Ich, Velvet, Flukes, and Columnaris. However, bettas could also be rubbing due to inappropriate water conditions, small tank size, external stimuli, and self-reflection.

As we move forward, I will present all possible causes for rubbing among betta fish, and what steps you should take to treat them. I will also discuss the unique phenomenon of glass surfing, and it may represent and how to stop it.

Why is my Betta Fish Rubbing Against Stuff Like Rocks, Plants, Filters & Glass?

Is it normal for betta fish to rub against plants, rocks, filters, and even glass? Well, it isn’t necessarily typical, but it isn’t abnormal either. It will occasionally happen whenever your beta develops an itch.[1]

Fish don’t have hands. The only way to scratch their itchy skin is to rub it against the objects in their tank. You should only grow concerned if this behavior persists. You should also show concern if additional symptoms accompany the rubbing.

Some fish can injure themselves by rubbing against sharp rocks and objects. They also run the risk of losing their scales. This is why you have to get to the bottom of the rubbing. Common causes of this behavior include:

1. Diseases

If your betta is rubbing against rocks or even digging around the substrate, you must consider it might have contracted illnesses and infections such as:

  • Ich Disease – Ich is the first illness most aquarists consider in such situations. A parasite causes Ich.[2] The disease is highly contagious. If your betta has white spots all over its body, you can probably blame Ich for its behavior, in which case it should be quarantined to protect the other fish. As you might expect, Ich irritates the skin, compelling the betta to scratch by rubbing against objects in the tank.
  • Worms – Another prominent cause of rubbing in bettas is anchor worms. They also cause labored breathing, lethargy, and soreness, not to mention ulcers. Anchor worms are not that hard to diagnose. They are visible to the naked eye. You will typically see white strings hanging from the betta’s body.
  • Velvet – Like Ich, velvet is relatively easy to identify. Fish with the illness have a coating that mimics gold dust. It covers their bodies, alerting you to the presence of the disease. A fish with velvet is highly likely to scrape against the objects in its tank.
  • Flukes – Gill flukes are parasites that will damage your betta’s gills, covering them in mucus and causing labored breathing in the fish.[3] Gill flukes can also cause rubbing and scraping in fish.
  • Columnaris – Bettas with this sickness have growths around the mouth and gills that look like cotton. If your fish is rubbing against objects and you have seen these growths, you can blame the behavior on Columnaris.

These are some of the most prominent illnesses that can encourage rubbing and scraping in bettas. But they are not the only ones. Any illness that irritates your betta’s skin will attract similar behavior.

Also Read: Betta Fish Diseases

2. Safety Issues

Sometimes, a fish looks like it is rubbing against rocks, plants, and the substrate when it is merely looking for a place to hide. You will see this in fish that do not feel safe in your aquarium. If they cannot find sanctuary among the plants or behind decorations, they dig into the substrate.

You will also see this behavior among fish that are new to a tank. The transfer to a new container can cause shock, creating a sense of insecurity and stress and forcing your bettas to act erratically. The effect is more prominent when a dominant fish is already present in the tank.

3. Lack of Food

Again, you need to make sure that your betta is indeed rubbing against the plants and rocks. The fish may be merely looking for food. If the meals you offer are insufficient, your bettas will look for additional nourishment sources in their tank.

In some cases, they are merely looking for the leftovers that are still floating around the aquarium. When food goes uneaten, it will inevitably sink into the substrate, unless the gentle current of the tank forces the leftovers into the plants and rocks.

4. Reflection

Fish are not the smartest creatures. If the light inside the tank is brighter than the lighting outside, your betta will eventually notice its reflection in the glass. In response, it might attempt to reach that reflection, rubbing against the glass walls in the process.

Your betta is unlikely to harm itself by rubbing against the glass. But the ordeal can induce stress in the fish, and stress is always bad news. You may suspect that this is the case if the betta’s behavior occurs during the day and diminishes towards nighttime.

5. External Stimuli

If the reflection isn’t the cause of your fish’s behavior, some external factors might have aggravated the betta. For instance, a bright object. If the external stimulus is strong enough, the betta could go so far as to dig into the substrate.

If your betta is intimidated by the views outside, it may seem that it is rubbing against objects while the fish is, in fact, looking for a place to hide. Sometimes the source of stress could be the view of its owners. Try to determine whether your fish acts like that merely once it sees your figure.

6. Temperature & Water Conditions

Bettas live in waters whose temperature ranges from 78 to 80 degrees F.[4] If the temperature undergoes drastic changes, either rising or falling suddenly, the shock will compel your bettas to react aggressively and erratically. Temperature shock is dangerous. It is more than capable of killing your fish.

Poor water conditions can also cause physical irritation that will encourage your fish to rub and scrape against the aquarium’s objects. Such conditions include high ammonia, nitrite, and nitrate levels, the wrong pH, and the presence of elements like chlorine.[5]

7. Inadequate Tank Size

In many cases, fish rub against objects because they are stressed. One prominent cause of stress in bettas is a small tank. If their tank is not only small but overstocked, the lack of freedom and the eventual competition for resources with other fish will cause distress in your bettas. 

That will drive them to manifest odd behavioral patterns such as rubbing and scraping. That could also be the case if your betta shares a tank with other fish, and the aquarium is too small for holding on its occupants.

How to Treat Bettas That Frequently Rub?

If your bettas are always rubbing against objects in the tank, these are a few of the ways you can help them. Naturally, the treatment depends on the underlying cause:

1. Diseases

As was mentioned earlier, diseases may force your betta to rub against objects. However,

if you are not familiar with the right medication to use for your betta’s disease, I recommend consulting an expert. Using the wrong drugs might harm and even kill your fish. If you have some experience in the field, you may treat your fish with the following:[6]

  • Velvet – If your betta doesn’t have velvet, you can add aquarium salt to the tank to keep the disease away. If velvet is already present, you can use Malachite Green-based medications, such as the KORDON Malachite for Aquarium (link to Amazon)
  • Ich – If your fish has Ich and its tank is more than 5 gallons, raise the temperature to 85 degrees F to kill the parasites. If the tank is smaller than 5 gallons, raising the temperature will kill the fish. You should also consider medications to treat the parasite, such as the Kordon Rid Ich Plus (link to Amazon).
  • Columnaris – If your betta has Columnaris, you can treat it with Maracyn and Marycyn-Two. Other options include oxytetracycline, erythromycin, and Kanacyn, to mention but a few. I personally recommend the API Aquarium Fish Medication (link to Amazon) to treat this disease. 
  • Flukes – If your fish is lethargic and gasping for breath on top of exhibiting the rubbing behavior, it probably has gill flukes. You have to clean the tank thoroughly, along with performing 50 percent water changes. You can also expose the betta to a salt bath to remove the mucus and the parasites. Try a combination of formalin and malachite green if the salt bath fails. There is also Paragon, Proxipro, and Clout.[7]
  • Worms – If your bettas have anchor worms, bathe them in potassium permanganate (10mg per liter) for 10-30 minutes. Along with using products like Paragon, you can also perform a 70 percent water change.

Also Read: Curled and Clamped Betta Fins

2. Water Conditions

If the water conditions are to blame for your betta’s behavior, perform the relevant tests to identify the culprit. I consistently use the API Reef Master Test Kit (link to Amazon) to get a better picture of my water conditions. It is reasonably priced and gets the job done. Within minutes, it will measure your ammonia, pH, nitrates, and nitrites in your tank.

If the pH is too low, adjust and maintain the carbonate hardness.[8] This will prevent drastic changes in pH. You can reduce ammonia levels by performing water changes and removing rotting organisms and leftovers. That will also get rid of elevated nitrates and nitrites.

Try to keep your bettas in the most prominent tank possible. The bigger the tank, the longer it takes for waste and toxins like ammonia to accumulate. You should also limit the number of bettas in your tank, not to mention avoiding overfeeding.

The more food your fish eat, the more waste they produce. If you don’t have a proper filter, make sure to get one.

3. Stress

If stress is driving your fish to rub against objects, identify and eliminate the source of it. That includes small tanks and overcrowding. If the betta’s tankmates are bullies, remove them. If the tank doesn’t have any hiding spots, add more plants and rocks.

If the betta is new, take the time to acclimate it to limit the shock it will experience once you move it to a new tank. If the conditions in the tank are appropriate and your betta has nothing to fear from its tankmates, the stress will fade along with symptoms like rubbing.

4. Reflection

If you don’t want your fish to rub against the glass, turn the tank lights off or dim them a little. Do this whenever the lights in the room are switched off. This will eliminate the reflection. You can achieve similar results by placing a lamp near the tank.

You should also avoid putting your hands on the glass or standing too close to the betta fish’s tank. That will enhance its reflection and intimidate it. Consequently, your fish may swim its way behind rocks or sharp objects, possibly getting injured along the way.

How do I Stop my Betta Fish From Glass Surfing?

Follow these steps to stop your betta fish from glass surfing:

  • Perform 10-15% water changes weekly to lower the levels of ammonia and toxins.
  • Remove decorations and plants if your tank is overstock.
  • Avoid dominant and aggressive companions, such as male bettas.
  • Use plants and decorations if your tank is empty and features reflections.
  • Use a dark backdrop to obscure your betta’s view. 

1. Adjust the Water

If the aquarium is dirty, and the toxins have accumulated and haven’t been appropriately cycled, glass surfing will ensue. Get a testing kit and ensure that all the parameters are within the relevant ranges.

Make adjustments to the pH, temperature, nitrate, nitrite, ammonia levels, and hardness. Carrying out regular water changes will take care of most of these factors.[9] The average aquarium requires 10-15% water changes weekly. Heavily stocked tanks require 20% water changes per week.[10]

2. Avoid Overstocking

Overstocking causes stress in fish. It limits their freedom while also increasing the concentration of toxins in the water. This eventually leads to violence and behaviors like glass surfing, especially with bettas, which are not necessarily schooling fish.[11] 

You can solve this issue by reducing the number of fish or getting a bigger tank that can accommodate all your bettas. If all you have is a single betta fish, consider removing objects like rocks, plants, and decorations.

3. Choose the Tankmates Properly

Male bettas cannot live with their kind.[12] You are encouraged to keep only one male in each tank. Otherwise, their territorial nature will lead to violence. They are not compatible with small, peaceful fish or species with flowing tails.

If you select the wrong tankmates, the resulting bullying and aggression will lead to glass surfing. You have to keep your male bettas with compatible fish like Tetras, Poecilia, and Rasboras. These species are quite docile and less likely to alienate your betta.

Also Read: Betta Fish Swimming Vertically

4. Avoid Overfeeding

Don’t overfeed your betta. It has a tiny stomach. Overfeeding can cause illnesses like swim bladder disorder that will lead to glass surfing.

Feed your bettas once or twice a day. Give them small portions.

5. Plants & Decorations

If your tank isn’t overcrowded, I suggest offering your bettas more plants. Vegetation will give the fish peace of mind because they provide additional hiding places. Plants will also reduce the chances of the fish seeing its reflection.

Make the tank environment interesting for your betta. Add rocks, decorative objects, and even caves. This will give the fish places it can explore, keeping it occupied. Decorations also provide hiding places and lower the chances of glass surfing.

6. Use a Dark Backdrop

If the glass surfing is the result of objects or occurrences outside the tank, add a material (non-reflective) to the tank’s sides to obscure your betta’s view.[13] However, it should be noted that glass surfing isn’t always an issue. 

If you ignore it in new fish, the behavior will most likely disappear once the betta grows accustomed to its new home. Some bettas act this way whenever they observe a change in their aquarium. If it occurs occasionally, it shouldn’t worry you.

And if you’ve tried to stop the behavior and you have failed, let the matter go. Sometimes, you cannot do anything to prevent a betta from glass surfing. Sometimes, the fish’s personality is to blame, in which case, you have no way of changing it.


Bettas typically rub their body against objects once their skin itches. Since they don’t have hands, they use rocks, plants, filters, and sometimes even the tank’s glass to eliminate the feeling. That itch could represent a disease, such as Ich, worms, velvet, and flukes.

The phenomenon could also occur in healthy bettas, especially when their water conditions are poor and their tank is too small. That may also be expressed by glass surfing. In this case, you should conduct frequent water changes, get a bigger tank, and eliminate bullying companions.