Have you noticed a thin oily film on the surface of the water in your aquarium? Don't be alarmed, almost every aquarist faces this problem. This film not only spoils the appearance of the pond, but also interferes with normal gas exchange, which can be dangerous for your fish.
There may be several reasons for its appearance. Most often, the culprits are fatty food residues, dust, bacterial outbreaks, or substances secreted by certain types of plants and driftwood. Sometimes the film forms due to insufficient water movement at the surface.
The good news is that it is fairly easy to get rid of. The simplest way is to place a clean sheet of paper on the water and then carefully remove it. The film will stick to the paper. But for a long-term solution, it is important to understand and eliminate the specific cause of its occurrence.
A film on the surface of the water in an aquarium is most often the result of an excess of organic matter: food residues, fish waste, decaying algae, or fats from food. Such a film interferes with gas exchange, and fish may experience a lack of oxygen. The problem arises when there is insufficient filtration, infrequent water changes, or overfeeding of the inhabitants. Getting rid of the film is easy: change some of the water, clean the bottom, check the filter, and do not feed the fish more than they can eat in a couple of minutes. Good water circulation and regular maintenance will prevent the film from reappearing in the future.
Types of films
Depending on the cause, one film can be very different from another.
In some cases, it may resemble a transparent layer of oil that shimmers with a rainbow under the flow of light. The best comparison is gasoline on a wet surface. If the film is like this, it is probably an oil stain.
In other cases, the film in the owner's aquarium may appear gray or white, sometimes difficult to see, and may even clump together into flakes when stirred.
This thin white residue is a protein film and is especially common in Betta aquariums. Don't worry, you can get rid of this protein buildup just like any other film on the surface of the aquarium.
What causes film to appear in an aquarium
You don't need much oil to create an impressive stain. In fact, one or two drops are often enough. In some cases, this problem can be solved simply by eliminating the cause.
Grease from hands
Aquarium owners have many reasons to get their hands wet. Whether it's catching a sick fish with a net or adjusting plants, you need to dip your hands in the water.
In fact, this is the most common cause of a greasy film on the water.
This is because the pores of the skin naturally secrete oil. It is such a small amount that it is not even noticeable at first glance. And that's not including hand lotion or other moisturizers that people use to care for their hands.
When the hand comes into contact with water, this oil is washed away and forms an oily film on the surface of the aquarium.
How to prevent it
The solution is simple. If the owner plans to immerse their hands in the aquarium, they will first need to wash them thoroughly. It is also necessary to rinse off all the soap, otherwise it will end up in the aquarium.
The best option is to buy a pair of protective gloves for the aquarium and wear them when you plan to work in the aquarium.
Fish food
It is no secret to experienced aquarium owners that many types of fish food contain some form of fat.
When it's time to feed the fish, the food dissolves and all the fats and proteins float to the surface.
This is a particular problem if the owner has a habit of overfeeding the fish. Any food left over after feeding will continue to dissolve and release the fats inside. This is another important reason not to overfeed your fish!
Fish feces
It's inevitable. Every fish will eventually dump waste into the aquarium. And it's oily waste. Because fatty food means fatty feces!
In addition, the natural digestive system of fish produces oils and proteins when breaking down food. And when waste is released from the fish's intestines, the fat inside the feces rises to the surface.
Filters and pumps
A new filter can cause a huge oily stain.
This is a common problem, as filters and pumps are often treated with a small amount of oil to lubricate their moving parts. Not to mention other oils left over from the manufacturing process.
The owner can minimize the amount of oil released by the filter into the aquarium by washing the filter before use.
Dead fish
One fine day, all the fish go to fish paradise. If the body is not removed immediately, it will release fats and oils into the water as the decomposition process begins. This problem is fraught with a truly unpleasant odor.
So, if the owner notices an oily spot on the surface of the water, it is high time for them to do a fish roll call to make sure that all individuals are accounted for.
Poor aquarium placement
An oily film on the surface of the water may be the result of the owner's mistake in placing the aquarium.
It's easy to forget that those tiny clouds from aerosols and perfumes have to settle somewhere. And if they settle in the aquarium, they can cause a film to form on the surface of the water.
Similarly, if the aquarium is located too close to the kitchen, the grease produced during cooking can settle on the surface of the aquarium, causing an oily film to appear.
Ideally, the aquarium should be placed as far away from these sources of pollution as possible. Choosing the right location for the aquarium will help avoid such problems.
Bacteria
Bacterial biofilms on the surface of the tank are usually silvery-white in color. When touched, this “scale” will break up into smaller pieces. Some of them are so-called iron bacteria, which oxidize dissolved iron and extract energy from it.
Are these films dangerous?
There is no denying that the film covering the surface of the aquarium is unsightly. But it is important to understand the danger it poses.
A small amount of grease will not harm the fish. However, if it accumulates, the oily film covering the surface of the aquarium can cause the fish to suffocate. Oxygen enters the water through the surface of the aquarium. And, of course, everyone knows that oxygen is very important — fish need it to breathe. A thick film can act as a barrier, preventing oxygen from entering the aquarium.
Even a tiny spot reduces the amount of oxygen entering the water. And in an overcrowded tank, this can spell disaster. Especially considering that the film not only traps oxygen, but also traps carbon dioxide!
Given the risk to fish, there is no logical argument for not removing such spots from the aquarium.
How to get rid of films on the surface
Considering all the reasons, every owner may wonder why there is no grease floating on the surface in every aquarium. After all, the reasons for its occurrence are quite common.
The answer is simple: constant water movement, especially surface agitation, causes the water to churn and swirl. This mixes and disperses the small amount of grease, which is ultimately removed when the water is changed and the filter is rinsed.
This is why aquariums in which the water does not move are most at risk of surface stains.
Immediate removal
So, there is a giant film on the surface of the water, and the owner wants it to disappear immediately.
He can do it easily. He only needs one piece of equipment. Even better, there is a chance that he already has it nearby.
Paper towels or newspaper! These absorbent superheroes remove any grease they touch.
Removal process:
- The first thing to do is to turn off all filters, pumps, and nozzles—in short, everything that causes water movement in the aquarium.
- When the film settles, spread a paper towel or newspaper over the surface for a few seconds. Before removing them, make sure that the film sticks to the surface of the paper towel or newspaper.
- If the tank is large or the area of the stain is particularly large, you may need to repeat this process several times until the film disappears.
Alternatively, if the aquarium owner has a steady hand, they can carefully pour the film from the surface into a container — measuring cups are perfect for this. But be sure to make sure they are clean and free of soap!
Water movement
Water movement is the key to avoiding an unsightly layer of protein and fat on the surface.
There are several ways to achieve this:
- by directing the filter nozzle at the surface of the aquarium;
- using a spray bottle;
- or even bubbles from an aerator.
These devices will stir up all kinds of debris and prevent it from sticking together to form a film.
If there is an oily spot on a small area of the aquarium, this may indicate a “dead” spot in the tank, i.e., a place where water does not circulate. In this case, you need to adjust the position of the filter outlet and power heads so that the water circulates throughout the tank, preventing the appearance of stains.
Using a float (skimmer)
Simply attach the surface skimmer to the aquarium filter inlet, and the floating film will disappear in minutes, as if by magic!
If the film formation problem is constant, then a surface skimmer will become an aquarist's best friend!
The principle of operation is quite simple. The skimmer has two openings: one at the top and one at the bottom. But we are most interested in the top one.
This opening is aligned with the surface of the aquarium. As the filter draws in water, any floating grease, algae, and other debris is sucked through this opening, where it is filtered.
Electric surface skimmers are available. However, experienced aquarists prefer those that attach to the filter inlet. Electric ones do not work better, are expensive, and take up another precious outlet on the extension cord.
Do not confuse a surface skimmer with a protein skimmer. A surface skimmer removes floating film from the top of the aquarium. A protein skimmer uses bubbles to remove unwanted debris from under the water and is usually only used in marine aquariums.
Although the film in the aquarium may look unsightly, it should not cause the owner too much of a headache. Using the tips listed above, you can easily solve this problem and forget about it.
So, a film on the water is not a death sentence for your aquarium, but rather a signal that something has gone wrong in the established balance. Most often, we ourselves are to blame: overfeeding, lack of care, or poor filtration. But now you know that this is easy to fix.
The main thing is not to panic. Start with the basics: check the filter, remove food debris and trash from the bottom. Try removing the film with a paper towel or increase the water movement at the surface. Often, these simple steps are enough to get the water breathing again.
Remember that the clear surface of the water is the lungs of your aquarium, through which vital gas exchange takes place. Regular maintenance, moderate feeding, and good filtration are your best allies in combating this problem. Take care of your underwater world, and it will reward you with the cleanliness and health of its inhabitants.
