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How to Start a Freshwater Tropical Aquarium

I have several freshwater aquariums, including 10-gallon and 30-gallon tanks. I enjoy maintaining and decorating aquariums.

My freshwater aquarium with tropical fish

My freshwater aquarium with tropical fish

Advice on Aquarium Setup, Maintenance, and Decoration

Setting up a freshwater aquarium is not as hard as you might think! Need some helpful advice? Are you new to this hobby but need a few starter tips? Whether you're a beginner or an aquarium enthusiast, you've come to the right place!

Proper water chemistry and fish basics are essential to having a healthy, beautiful aquarium, and it's not as difficult and time-consuming as you might think. Do you also need some advice on decorating your aquarium? I've got some suggestions on that, too! Just a little bit of research and patience, and you'll have that picturesque aquarium that you've always desired!

Water Chemistry and Aquarium Setup

The first things to consider when deciding what kind of freshwater fish you will acquire are tank size, size of fish, compatibility of fish, and water chemistry basics. All freshwater fish typically have the same kind of water requirements, aside from goldfish (carp), which require no heater. Goldfish are strictly cold-water fish.

Tank Size

So, let's start with tank size and kinds of tropical fish. Most tropical fish will get to be as large as one to three inches in length. A good rule of thumb for tropical community fish is 1" of fish per gallon of water. If you plan on having more than 10 fish (depending on their adult size), you may want to invest in a larger aquarium such as a 20- or 40-gallon tank.

Other Equipment for the Tank

You will also need to purchase a hood with a UV light. Most aquariums that are sold in the stores include this. For tropical fish, always make sure to purchase a thermometer. These may be purchased at your local pet store. They have adhesive on them and may be placed on the outside of the aquarium. Along with this, you will need to purchase an aquarium heater (most heaters are easy to use and have valves for controlling your water temperature) and a filter.

The filters come in all kinds and sizes. I use a filter that fits over the outside of the aquarium, and these filters work very well! They are power filters and have filter cartridges that must be replaced approximately every two weeks. Under-gravel filters are preferred by some individuals, but power filters are the most popular. They are easy to maintain and work extremely well at keeping your aquarium water filtered. (See the photo under the article section "Cleaning Your Aquarium").

Learning About Water Chemistry

The next thing to discuss before even considering what kinds of tropical fish you will buy is water chemistry. This is generally the part of owning an aquarium that most people fear. But, fear not; once you are experienced with this, you will have no problem at all! I recommend purchasing the book A Guide to Freshwater Aquariums by Mike Wickham. This book has everything in it and is an easy read. It tells you everything you need to know about starting your freshwater aquarium and answers any questions you might have along the way after you've started your hobby.

Steps for Setting up Your Aquarium

  1. After purchasing your aquarium and adding gravel, which should be about 1 to 2 inches deep, it's time to add the water. And, always make sure you wash your store-bought gravel very well before filling up the aquarium. This removes any dust particles that are present from the manufacturing plant.
  2. I put the gravel in the aquarium; then, I start adding water and rinsing the gravel while it is in the aquarium. I use a one-gallon bucket to remove the dirty water and continue rinsing the gravel with more water until the water is relatively clear.
  3. Now, it's time to start filling it up with water! Again, I use a bucket to do this. You can probably find a plastic bucket at any hardware store or at any Walmart or Target. They may even have something like this at your local pet store.
  4. After the aquarium is full of water, I put my heater in the aquarium and plug it in. You will be able to gauge the temperature by observing the thermometer on the outside of your aquarium. Tropical fish need a temperature of 78ºF to 82ºF.
  5. The next thing to do is to use something to remove the chlorine, chloramines, and any heavy metals from the water. This can be done in one step. I use something called Stress Coat by Aquarium Pharmaceuticals. Follow the directions on the bottle and apply it to your aquarium water.
  6. You will want to adjust your pH (acidity of the water). pH falls into one of three categories: acidic, neutral, or alkaline. A proper pH should run between 6.8 and 7.2, with 7.0 being an exact neutral pH. Tap water in most cities is usually extremely alkaline, and fish will not tolerate this for very long. To start your aquarium correctly, I recommend getting a tablet that can be put into the aquarium to set the pH at neutral. Jungle "Correct pH Tank Buddies" is a good one to buy and can be bought at any store that sells aquarium products. Again, always read the directions so that you know how many tablets to put into your aquarium.
  7. I advise letting your aquarium set for 24 hours while maintaining the correct temperature and correct pH. To test your pH, purchase test strips that can be quickly dunked into the aquarium and red momentarily. This will help you to gauge your water chemistry. This is the start of setting up a beautiful aquarium!

While you're waiting on your temperature to get regulated, this is a good time to buy any decorations that you desire! Always make sure that any ornaments that you purchase are aquarium-safe! If you choose to use plastic plants or live plants, that is totally your decision. I use a combination of both.

Types of Fish to Include in Your Aquarium

The next step is to buy your fish. You have many choices here. I do not have any live-bearing fish, such as guppies, platies, and mollies. These tend to reproduce like crazy, and you will end up with a lot of little baby fish in your aquarium. I prefer the non-live bearers, such as barbs, tetras, danios, and corydoras (catfish).

Angelfish are beautiful but get up to 5" to 6" in length and are a little more on the aggressive side. This does not mean that you cannot have a beautiful, healthy community aquarium and incorporate angelfish into it, but remember to have a large tank.

Always remember to get maybe three fish (for small aquariums, such as 10 gallons) to start with and 6 to 9 fish to start with for 20 to 40-gallon aquariums. This is because the filtration system that is composed of beneficial bacteria is not yet established. I will discuss this later in the article. Here are some pictures below of common species of fish sold at the pet stores.

Benefits of Using Live Plants

Live plants are an excellent addition to your aquarium. They help to oxygenate the water, provide extra food for the fish, and compete with the algae for nutrients. There are many different kinds of freshwater plants. Some are bulbs, broad leaf plants, and aquatic grass. I am not as well versed in my plant varieties as I am in my fish.

The plants will need to be pruned periodically. You will also need to provide plant food for them on a weekly basis. Just make sure that the plant food is safe for your fish. One other product that I use is liquid carbon. Plants regularly take in carbon dioxide and release oxygen into the environment. There is not a lot of carbon dioxide within an aquarium.

You can do one of two things. You may buy the liquid carbon and apply that daily or every other day, or you may obtain a CO2 pump. A CO2 pump constantly pumps carbon dioxide into your aquarium, and the plants thrive on it. I do not use this, only because I prefer to have a little more control over the amount of carbon that is going into the aquarium. Liquid carbon is easily obtained at any aquatics store, and it does work!

So, remember to use this along with your plant food, and you will have healthy plants. Again, always follow the directions, and never add more than the directions specify.

Feeding Your Fish and Cycling Your Aquarium

Tropical freshwater fish eat tropical flake food. Their diet is comprised of bout 50% protein, unlike goldfish (which are primarily vegetation eaters). I use TetraMin tropical flake food, and I feed the fish once up to three times a day. Never overfeed your fish. It's better to feed them several times a day, giving them small quantities of food, than feeding large portions once a day with most of the uneaten food sinking to the bottom.

You may also want to supplement their diet with frozen blood worms, and you can purchase these at any pet store that sells aquatics. These are rich in protein, and the fish go crazy after them!

What Is Cycling?

A very important part of having a new aquarium is 'cycling' the aquarium. And, no, you don't have to do anything except monitor the nitrite and nitrate. This can be done by using your test strips. This is part of the natural ecosystem of any aquarium. The fish will begin producing waste that must be broken down by beneficial bacteria that are naturally present in your aquarium, but in a new aquarium, these bacteria are not yet present in high concentrations. The object is to build up the beneficial bacteria so that the nitrites (which can be very toxic to your fish) can be broken down into nitrates (which are less toxic to your fish).

The bacteria in your biological filtration feed off the ammonia that is excreted by the fish and any decaying matter in the aquarium. The ammonia is broken down into nitrite, and this is broken down into nitrate. The cycling of an aquarium takes about two weeks. A few days after adding your fish, you will see the nitrite levels go up. Don't be alarmed! This is supposed to happen. The object is to not have nitrite levels increase so much that they poison your fish.

If you add your fish slowly when starting your aquarium, your fish will be just fine. Their water may become cloudy during this cycling process, but this is normal. Do not be alarmed if this happens. It's very common, and there is no need to change the water unless the nitrites are registering extremely high and your fish are showing signs of stress (clamped fins and gills pumping heavily). If the fish look fine, do nothing.

There are products available to help neutralize ammonia, but this is rarely needed. The levels of ammonia have to become high enough to build up the beneficial bacteria, or else the bacteria will have nothing to feed on. If you keep neutralizing the ammonia and nitrites, then you will never get the bacteria levels to an acceptable level. There is also a product called Stress Zyme by Aquarium Pharmaceuticals. This product contains live beneficial bacteria, and I have found it to be extremely helpful. Patience is the key when starting a new aquarium!

Several products I use on a regular basis

Several products I use on a regular basis

Cleaning Your Aquarium

After your aquarium has cycled, you will want to start cleaning your aquarium on a regular basis. A good rule of thumb is to do a 25% water change at least every week and to do a more thorough cleaning with a siphon every two weeks. You may even want to do this once a week. I know of some people that do this.

Using a Vacuum Siphon

A vacuum siphon consists of a long tube with a large tubular connection on the end. This is used to vacuum your gravel. There is a lot of bacterial filtration that takes place in the gravel, but there is a lot of decaying matter that is not picked up by all of the beneficial bacteria, and this will need to be cleaned periodically. Remember, your fish are not in a natural environment, and it is up to you to make sure that it is kept in check.

Siphons are very easy to use. I get my bucket and put the end of the siphon in the bucket and put the larger end into the aquarium gravel. I pump the siphon up and down into the gravel until I get a suction started. Continue putting the siphon into the gravel using up and down movements as the water is vacuumed into the bucket. You will be surprised how much debris is removed. You will see this when you empty the bucket of dirty water. I always go over the entire gravel bed when I do my cleanings.

When your bucket is full of dirty water, take the end of the siphon out of the gravel and out of the aquarium, and the suction will cease. For warm water aquariums, always make sure that the new water that is put into the aquarium is the same warmth as the water that's in your aquarium. This will reduce the stress on your fish.

Testing and Adjusting the pH

Also, make sure to add your chlorine and chloramine neutralizer to your newly added water. Take a test strip and test the chemistry of the water. If the pH is fine, then do nothing. If it is too acidic or too alkaline, then treat it accordingly. There are liquid products sold in the stores to adjust the pH.

Never adjust the pH more than about two points within about 24 hours! If you do, your fish may become stressed, and when this happens, they are very prone to disease. Nothing will kill a fish faster than stress! Also remember to invest in an algae scraper. This will help to scrape any unwanted algae from your aquarium glass.

Cleaning the Filter Pump

Another thing that must be performed periodically is cleaning your filter pump. Besides changing the actual filter cartridge, the pump gets kind of gunky after a while, and this may slow the filtration process. If the water looks like it is not being pumped adequately, then it's time to unplug the pump and take it to a sink in your home and clean it out. This may be done with an old toothbrush. Just make sure that there are no cleaning chemicals on the toothbrush that you use. You can take apart certain parts of your filter and clean it, and I guarantee that you will notice a huge difference in the filtration process after cleaning it!

Power filter

Power filter

Algae scraper, bucket, and siphon

Algae scraper, bucket, and siphon

When Your Fish Get Sick

Many times you may have certain diseases pop up from time to time. Keeping your aquarium balanced and clean is a good preventative against disease.


One of the most common diseases to occur in freshwater aquariums is Icthyophthirius multifilis (also known as Ick). This presents itself as little lesions that look like grains of salt on the body of the fish. They may be present on any part of the body. This is very easy to treat, provided you treat it with the proper medication. My Buenos Aires Albino Tetras contracted this not too long ago, and I was advised by a very knowledgeable pet store associate to use a combination of formalin and malachite green. This product is sold as a combination medicine and may turn the water a bluish color; however, I never noticed any color change in my aquarium. I used it for three days, and then after that, I performed a 20% water change.

When you are treating any kind of disease, it is wise to remove the filter cartridge from your filter pump. The carbon will absorb the medication and thwart the treatment. Most ailments are treated for no longer than about a week. Ick is very easy to treat, however. The Ick is gone from my fish, and they look beautiful now! There are also 'over the counter' remedies that treat a variety of ailments.

Fish can contract anything from fungal diseases and parasites to bacterial diseases. The trick is catching it before it is allowed to progress, so always keep a close eye on your fish.

Enjoy Starting Your Aquarium!

I have covered a lot of information in this article, and it is not meant to deter people from starting an aquarium. After you get your aquarium set up and cycled, it will be a beautiful addition to any room, and it will make quite the conversation piece. It is also extremely relaxing to sit back and watch the beautiful masterpiece that you have made despite all of the hard work that goes into having a thriving, gorgeous aquarium!


Dana Stamps (author) from Wichita, Kansas on May 18, 2013:

Thank you! Yes, aquariums are something that I definitely have a lot of experience with. I appreciate your awesome ratings! :~)

Judah's Daughter from Roseville, CA on May 18, 2013:

Wow, you have a lot of experienced knowledge to help people, step-by-step in setting up and maintaining a lovely fresh-water aquarium with beautiful, healthy fish. I can see why this can be a hobby for so many people! Very informative! Voted Up, Useful and Interesting!

Dana Stamps (author) from Wichita, Kansas on May 05, 2013:

Thank you so much for your kind words! I appreciate you comment on my pictures. Yes, aquariums can be tricky, but when all is well, they are so beautiful! Right now, one of my aquariums has a bacterial bloom (whitish, milky colored water). It is murky, but it's because I added five more fish to my 30 gallon. I want to let everybody know that these things are to be expected, and generally they clear with time. It's the ecosystem working to create that balance that your aquarium needs to be a thriving successful aquarium. Usually, bacterial blooms clear within a few days and will not hurt the fish. The bacteria require a lot of oxygen, but if a person has an extra pump to oxygenate the aquarium, then there is nothing to fear. The worst thing that can happen is 'green water'. Sometimes the bacterial bloom which is caused by free floating diatoms can convert to a "blue-green algae", which is not truly an algae but a bacterium that photosynthesizes. Thank you, again, for your comment!

Ceres Schwarz on May 04, 2013:

Interesting hub. It's very useful for those looking to start a fresh water aquarium. Your images are all lovely and really show the beauty of the aquariums.

Dana Stamps (author) from Wichita, Kansas on May 03, 2013:

Haha! Thanks for the comment! It's really not hard, and you will be able to enjoy a nice, relaxing ecosystem in your home. Aquariums, aside from any hassle, are quite relaxing. :)

Don on May 03, 2013:

This makes me want to start one !!!

Dana Stamps (author) from Wichita, Kansas on May 03, 2013:

Thank you! I really appreciate your compliment!

Chris Achilleos on May 03, 2013:

Hi Danast,

I have found your hub very interesting. You have provided great tips on how to start a freshwater tropical aquarium, and I must say that your own aquariums look amazing :)

Voted up, awesome and shared with followers!