Is it OK to clean your aquarium without removing the fish?

1. Yes, it is ok to clean a fish tank with fish in it. The fish will have different reactions to the cleaning process depending on the type of fish. Shy fish that hide are the fish most likely to be injured during cleaning, therefore be careful if disturbing hiding places.

 

 

 

2. In addition, when cleaning your aquarium with the fish in it, move gently and carefully, being aware of where your cleaning tools are, in relation to the fish.

 

 

 

Doing these two actions should keep problems from popping up while cleaning your aquarium while the fish are still in it.

 

 

Picture above: my 2.8 gallon nano aquarium

 

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How should you clean your aquarium with the fish still in it?

 

1. Why should you clean your aquarium?

 

 

 

2. Remove 10 to 50 percent of the aquarium water.

 

 

 

3. Clean the filtration system.

 

 

 

4. Trim any overgrown plants.

 

 

 

5. Clean the glass on the inside of the aquarium.

 

 

 

6. Refill the aquarium with pre-conditioned water.

 

 

 

7. Clean the outside glass of the aquarium and the area around the aquarium.

 

 

 

— Huge Update

 

Please note: When I mention the word “fish” in this article, that word is used for the purpose of illustration. It is not to suggest that it is acceptable to put fish in a small or nano tank. Far from it. Please don’t put fish in a small or nano aquarium. There is not enough room for the fish in a small or nano tank. Putting a fish in that environment is unkind to the fish.

 

 Yes. Go ahead, it’s ok…

 

 

In-depth answer to the question, “Is it OK to clean my fish aquarium without removing the fish?”:

 

 

Answer: “Yes, it’s ok to clean your aquarium with the fish still in it.”

 

Here’s why I am saying yes.

 

Some of what you’ll read online about cleaning a fish tank, with the fish still in it, is conjecture, but this article is based on decades of experience.

 

Except for a period of about 5 years, I have been keeping fish since 1988 (30 years). After so many thousands of aquarium cleanings, I have a pretty good idea of what reactions to expect from what fish when cleaning their aquarium.

 

Notice I didn’t say “what fish are feeling”. As far as I know, fish don’t have emotions.

 

Instead of emotions, fish have built in reactions to stimuli.

 

Here is a good example of “Stimuli equals’ reaction:”

 

What happens when you walk by your aquarium? Your form is a trigger to some fish to move to the front and top of the tank and swim briskly. They’re not doing this because they’re thinking, “If I beg for food I might get fed.” Instead, I suspect you would see this same activity in their native habitat during an insect swarm. “Swim around rapidly, get a lot of insects to eat.” “Sit in one place placidly and go hungry.”

 

This same idea of reaction to stimuli relates to how fish would react in the aquarium when it is being cleaned.

 

What “action equals reaction” is triggered if you insert a cleaning hose into the aquarium? That depends on the fish and how they behave in nature.

 

A cleaning hose might trigger fish that are chased and eaten as prey a lot, for example, neon tetras. The stimuli is that a predator (the hose) is nearby. Since stimulus equals reaction: The fish flee and hide, waiting for the “predator” (the cleaning hose) to go away. When you’re done cleaning their aquarium, the fish go back to behaving normally.

 

How does this affect you while cleaning the aquarium?

 

You probably won’t injure your fish if you’re aware of their hiding places.

 

The other type of reaction by aquarium fish to cleanings is going to be from fish that are both predators and prey in their native habitat (think of angelfish). They probably won’t react to stimuli as negatively, because they have less to fear in the wild. Their normal reaction to the cleaning hose, or your hands, is to move away from it, but continue swimming around like normal.

 

With these fish, your chief concern would be that they will not be cautious enough during tank cleanings. If you move too quickly, they could be injured. This isn’t likely, but it is a possibility.

 

If you move at a steady pace while cleaning the aquarium, the fish will be fine. It is probable they will be better off by you cleaning it, then to not clean it out of concern for your fish’s safety.

 

Now that you know it’s ok to clean your aquarium while the fish are still in it.

 

How do you actually clean an aquarium?

 

Below: A video showing the reaction of my danios to a magnetic algae cleaning tool. Not a very good video, but thankfully it is short. 🙂

 

 

How should you clean your aquarium with the fish still in it?

 

 

1. When and why should you clean an aquarium?

 

 

A planted aquarium may only need to be cleaned every few months and often just because of an issue that’s come up that requires you to clean your tank. For example:

 

 

* The death of an animal that goes unnoticed for a short while.

 

 

* Death of a plant creating an unusual amount of debris.

 

 

* Algae “bloom”. Not very common, but a water change and cleaning of the tank may be needed as two steps to get this issue under control.

 

2. Remove 10 to 50 percent of the water:

This is fairly self-explanatory. I use a siphon I made of hard plastic aquarium tubing and flexible aquarium tubing attached to each other. This small siphon allows me to remove most small items on the substrate that is distracting from the attractiveness of the tank. I have also seen water scooped from the tank using a measuring cup or a “turkey baster.”

 

 

How much water you change depends on why you are cleaning your aquarium. The bigger the problem or the dirtier the tank, the more water you’ll want to change.

 

 

I have two nano tanks. One is 2-gallons, and the other is 2.8-gallons. A one gallon water change is a massive change. 🙂

 

 

Since your fish are still in your tank, be careful that you don’t accidentally siphon, scoop out or squish any of your fish buddies. This is so easy to do in the small space of an aquarium.

 

3. Clean the aquarium filtration system:

 

If you have a filtration system (some low-tech or small tanks don’t) you may need to clean this system occasionally. How often you do this really depends on how much your “animal load” is. In other words, how many animals you have in your aquarium in relationship to the size of the tank.

 

A healthy aquarium with an extremely low animal load (as it should be!) will only occasionally need to have the filter cleaned. I clean my filters about four times per year.

 

New Hobbyists Beware! The filtration system can be a large source of nitrifying bacteria that your tank’s nitrifying cycle relies on. Over-cleaning the filter and therefore removing much of the bacteria could cause an ammonia or nitrite spike in your aquarium.

 

You are probably already aware of how harmful ammonia is to the fish and shrimp you keep in your aquarium. It can be a challenge to get the filter clean and yet keep the bacteria in place. It is so easy to upset the healthy bacteria balance in a nano aquarium so “tread lightly” in this area

 

Four very important ideas to protect the beneficial bacteria when cleaning your aquariums filtration system:

 

 

1. If you plan to clean and reuse the filter padding, rinse it in the tank water you have just removed. Don’t over-clean it. Don’t clean it in tap water.

 

 

2. Use permanent hard filter media inside your filter. This type of media is usually ceramic or plastic balls, pellets, noodles, etc. This type of media has a surface that helps cultivate more beneficial bacteria than would otherwise be available in your filtration system. More bacteria means you will have much less of a possibility of having your aquarium animals injured or killed by ammonia and nitrite. Do not clean this media! I never do that.

 

 

3. Do not clean the interior plastic parts of the filter canister or hang on the back filter. Only clean if you have to and then only minimally. The slime you feel on the plastic parts of the filter are beneficial bacteria. Make sure it stays in place while you clean your filter.

 

 

4. It is ok to clean the impeller and the housing where the impeller sits. Doing this insures that water flow through the filter won’t slow because of a dirty impeller.

 

Below, a picture of the “hard media” that I have in my hang on filter on a 30 gallon aquarium.

 

Hard filter media in a hang on filter

 

4. Trim any overgrown plants and remove any hair algae

A healthy nano aquarium will create an environment in which the plants will thrive. Healthy plants usually mean growing plants. This results from our original efforts to create a tank well suited for aquarium plants.

 

 

Since my efforts are usually to achieve a “landscaped” look in my aquarium, I need to keep the plants trimmed. How much or how little trimming is needed depends on the size of the nano tank and the type of plants growing in the tank.

 

 

If you have hair algae growing in your tank (this is very common even in healthy planted tanks) you’ll want to remove it. I’ve always used my siphon to “twirl” it up (like spaghetti). I recently came across an online post mentioning using pipe cleaners for this job. I haven’t tried this yet, but it sounded like an interesting idea. You can also, sometimes, grab it with your fingers.

 

5. Clean the glass of the inside of your nano aquarium

 

I am going to assume you have a glass aquarium and not acrylic, since acrylic is apparently easy to scratch.

 

 

For me, if I’ve had to clean the inside glass of an aquarium, it was because there was algae growing on the glass or there was a layer of hard water minerals around the top of the aquarium.

 

I’ve used all the following techniques to clean the inside glass of my aquariums:

 

1. I’ve used a magnetic scrubber. This is my preferred method. A magnetic scrubber comes in two parts; one part that works inside the tank that has the scrubbing pad on it and the other part is a handle covered in felt. The piece with the felt goes on the outside of the tank. The scrubby pad piece goes inside the tank. Both pieces have powerful magnets in them that hold them together through the glass. As you move the outside part of the scrubber over the glass, the inside part of the scrubber moves with it, cleaning the glass as it moves.

 

 

 

2. I’ve used razor blade scrapers. They worked well, but might be overkill for a nano aquarium.

 

 

3. I’ve also used plastic scrubbing pads. If you don’t mind getting wet, I have had excellent results with these. I always used pads I bought just for my aquarium. Only use the pads that are by themselves, not the pads with sponges attached. These sponges almost always have soap or wetting agents added to them before being packaged. Rinse your pads thoroughly in tap water before using them for the first time, just in case. Also, just an FYI: wash and throughly rinse your hands before putting them in the tank.

 

8. Refill your aquarium with pre-conditioned water, then clean any water spots on the outside of your aquarium.

 

Refilling your nano or small aquarium isn’t hard. Just fill a container with tap water. The water should be the same temperature as your aquarium water. Next, you’ll add your favorite water conditioner to your container. The chemical mix neutralizes the chlorine and chloramine and detoxifies heavy metals in your tap water. Last, pour the conditioned water gently into the tank, being careful not to disturb the substrate.

 

 

You’ll want to clean and dry any water or water spots on the outside of your tank. You spent a lot of effort to make your aquarium look attractive. Now you will make sure nothing is on the outside of the tank glass to impede enjoying your view. This also helps if you want to take pictures of your nano.

 

 

Those are the steps to cleaning your planted nano aquarium. It’s simpler than it sounds and will make your aquarium look outstanding.

 

Huge Update:   Why Clean Your Planted Nano Aquarium?   No, really. Why?

 

 

I am updating this article about 3 years after I first wrote it. I’ve learned a lot about cleaning nano (small) aquariums…or even large aquariums. I almost never clean my aquariums in the strict sense of the word.

 

You might wonder why.

 

I had stopped owning aquariums for several years because I hated the weekly cleaning time. Then I read the book “Ecology of the Planted Aquarium” by Diana Walstad.

 

In her book Diana suggested that cleaning a planted aquarium once or twice per year was plenty. The animals and the plants keep the tank clean. I took that to heart. In fact, the 30-gallon aquarium below has not been cleaned in the traditional sense of the word since I set it up three years ago.

 

BUT, I scoop out about two gallons of water per week (I use that water to water my houseplants and outdoor plants). I replace that water with filtered water or tap water.

 

I also clean the filters (I have two, a hang on filter and a cannister filter) about two times per year.

 

Easy peasy. Very little time spent, and you can see the results in the picture.

 

 

 

This pictures shows a 30-gallon planted aquarium that has been running for three years

 

What you’re seeing in this aquarium. 1. I just took out a huge mass of plant material so the tank looks a little barren. 2. I’m waiting for the driftwood to get soggy enough to sink. 3. The snails are chewing on food that the fish didn’t eat.