The information below is vital to starting and maintaining a healthy freshwater aquarium.

The Nitrogen Cycle

Before you set up an aquarium, you must understand how an aquarium works. Over time, uneaten food and fish waste (poo) accumulate in the aquarium. These wastes release ammonia into the water which is highly toxic to fish. Eventually, bacteria eat the ammonia and produce nitrite. Nitrite is also toxic to fish. Eventually, a second type of bacteria eats the nitrite and produces nitrate. Nitrate is not toxic to fish in low amounts and some of this nitrate is removed with regular water changes. The bacteria that are needed to make this process work are everywhere. They are outside in the environment and also inside of your home. And they are airborne. Once they find your aquarium and start to grow, the nitrogen cycle begins.

Do not add fish to your aquarium until the nitrogen cycle is in full effect. Doing so will likely result in sick or dead fish.

— Starting the Cycle

You can start the nitrogen cycle naturally, but it can take between 2 and 6 weeks for enough bacteria to grow to keep the water safe. To start the process naturally, you need to set up your aquarium and then put fish food into the tank. Use a little more food than you would for a regular feeding. The food will release ammonia into the water, attracting bacteria. If you don't want to wait for the natural process to take effect, you can use Tetra SafeStart Plus because it instantly starts the cycle and you can begin adding fish the same day.

Tank

If you are setting up your first aquarium, we recommend no more than a 10 or 20 gallon tank. 10 gallon tanks are common, inexpensive, and don't weigh more than 100 pounds when full so you may already have a suitable table or other furniture to hold it. Tanks sizes under 10 gallons are quite popular but may require more frequent water changes as there is less water to distribute waste. A 20 gallon tank will give you considerable flexibility when it comes to choosing fish and decor, but it can weigh up to 200 pounds when full so you may need to purchase a stand specifically for this size. 20 gallon tanks often come in to two varieties: long and high. We recommend the long version because fish swim side to side more than they do up and down. It's fun to think of a 20 gallon long as being a widescreen aquarium! When choosing tanks over 20 gallons, its important to evaluate the floor's ability to support the entire weight of the aquarium and supporting furniture.

When it comes to placing your tank, place it out of direct sunlight. While some sunlight is fine, direct sunlight can cause the water temperature to increase and kill your fish. Additionally, direct sunlight may cause any live plants to grow toward the light, which may not be aesthetically pleasing.

Before you finish setting up your aquarium, you may want to paint the rear of your tank a matte black. Many aquarists do this as it helps the fish feel safer as well as enhancing the color contrast of the fish and plants in the tank. It also hides wires and other aquarium items behind the tank. We recommend using a sponge brush with a dabbing technique as its gives good results on glass. Spray paint could be used but you will have to using tape to prevent overspray on the sides of the tank.

— The Hood

While a tank lid (hood) is not required to keep a healthy aquarium, it provides 3 main benefits. First, it fights evaporation which will keep overall water costs down. Second, it prevents fish from jumping out or pets from jumping in. Third, it can provide lighting. You'll need lighting to make your aquarium look aesthetically pleasing. Additionally, proper lighting drives the photosynthesis process in plants. When coupled with an outlet timer, your fish will also experience a natural and rhythmic night-day cycle.

You can find aquarium hoods at any pet supply store, but if you're crafty you can make one out of wood or glass. Some store bought hoods use flourescent T8 bulbs which can often be swapped out for more efficient LED bulbs.

Substrate

Substrate is the sand or gravel that you put in the bottom of the aquarium. We absolutely recommend sand for several reasons. Both play sand and pool filter sand work great. First, sand looks more natural because it is natural. Second, it makes cleaning easier. Because sand is quite dense, food and fish waste will generally settle on top. Since the waste won't get caught in the sand like it can with the gravel, its more likely that it will drift around and get sucked into the filter. Third, sand is less expensive compared to aquarium gravel. The only downside to sand is that it can be dusty and should be washed first. To wash sand, put some in a bucket with water and swish it around. The water will get cloudy and you can pour it out. Repeat until the water doesn't get too cloudy. As a final point, some fish such as Corydoras sift sand through their gills which they cannot do with gravel. Put the substrate in the tank before any water or decorations. The substrate should be at least 1/2" deep. For the best look, you want the substrate to be higher in the rear of the tank and slope down towards the front of the tank.

Some aquarists use coal slag as a substrate for its dark color. We do not recommend the use of coal slag because it has sharp edges that can cut your fish.

Filters

Aquarium filters serve 2 primary purposes in an aquarium. First and foremost, they house the bacteria that grows to drive the nitrogen cycle. This bacteria provides biological filtration. A high quality filter will grow plenty of bacteria to eat all of the ammonia and nitrite in the water. The second purpose a filter serves is mechanical filtration. By flowing water through a sponge or floss, tiny particles of waste and debris will get caught, keeping the water crystal clear.

Sometimes a filter will provide a 3rd type of filtration called chemical filtration. Generally, chemical filtration is provided by a form of activated carbon. The carbon will absorb chemical impurities in the water, but once saturated, the carbon must be replaced. Many aquarists keep perfectly healthy aquariums without the use of any chemical filtration, but if you are experiencing water discoloration, strong odor, or just want added filtration, activated carbon is a great remedy. Put 1 Tablespoon of carbon per 5 gallons of water in a mesh media bag (or nylon stockings) and put it in your HOB. Change the carbon during your regular filter maintenance or when water discoloration returns.

— Hang On Back Filters

Hang On Back filters are also called Power Filters. These filters are generally the best option for a single 10 or 20 gallon tank. They provide excellent mechanical and biological filtration and can be customized with filter media to your liking. We like the Marineland brand for its patented Bio-Wheel technology. The Marineland Penguin 75 is perfect for a 10 gallon aquarium. Spend a few dollars more for the Marineland Penguin 100 if you have a 20 gallon tank.

When we talk about customizing a hang-on-back filter, we mean using your own filter media instead of the manufacturer's filter cartridges. While the cartridges certainly work, you also get great results with a DIY approach. For example, Aquaclear Foam Inserts provide great mechanical filtration. Put one or two of those in the bottom of your HOB. Next, you'll want to put some ceramic filter media, like Aquaclear Biomax, on top of that. Finish off the stack with some polyester floss, or 100% polyester pillow stuffing, in a mesh bag and your water will be crystal clear! Floss is great at catching the tiniest of debris in the water; a process known as water polishing. Best of all, each part of this stack can be re-used. Just rinse them in aquarium water during your regular water changes.

— Sponge Filters

Sponge filters are rather unique as they are powered by an air pump. They provide an excellent amount of biological filtration, use very little energy, and are inexpensive. However, they only do a medium amount of mechanical filtration so your water may not be as clear with a sponge filter as it can be with a Hang-On-Back filter. Maintenance for a sponge filter is a extremely easy, as you only need to rinse the sponge in aquarium water during regular water changes.

If you want to give this kind of filter a try, we recommend searching specifically for a high flow sponge filter. The larger pores in a high flow filter allow for increased water flow. Additionally, filter cleanings are required less often because the filter won't clog up too fast.

Water

Generally, you will be using well water or tap water to fill your aquarium. If you are using tap water, you must condition it before adding it to the aquarium. We recommend API TAP Water Conditioner. Most tap water is treated with Chlorine or Chloramine that prevents humans from getting sick. Even in low amounts, Chlorines can easily kill fish and will certainly kill the bacteria that is driving the nitrogen cycle in your aquarium.

Do not use distilled water in your aquarium as it is unnatural and contains no minerals which benefit life in the aquarium.

— Oxygen

Oxygen is needed for life in the aquarium. Oxygen automatically and naturally diffuses into the water from the air. At the same time, carbon dioxide diffuses into the air from the water. This is a waste gas produced by the fish. When the water surface is agitated, it increases the rate of diffusion these gases. Generally, your aquarium filter will provide the necessary surface agitation to promote the diffusion of these gases. If you want to add even more surface agitation, using an airstone is a common way to do so. And at the same time, they provide a pleasing aesthetic effect.

Heater

It is always recommended to buy a temperature strip and a heater for your aquarium. A 10 gallon tank will need a 50-watt heater and a 20 gallon tank will need a 100-watt heater. Gallons x 5-watts = heater watts. Aquarium heaters are fully submersible and should be placed near the middle of the tank or where water movement is strongest—near the filter. You can position them vertically or horizontally. Some heaters are adjustable and all modern heaters feature auto-shutoff, so they won't overheat the water. For most freshwater aquariums, 25C (77F) is often considered the best overall temperature.

Plants

No aquarium is complete without a few select plants. Not only do they serve as a pleasantry for the eyes, they consume nitrates, further enhancing the biological filtration of the aquarium. The hidden bonus here is that there will be fewer nitrates available for unsightly algae to grow. Plants also can absorb some nutrients released by uneaten food and fish waste. Plants also provide hiding places for your fish. Fish will hide under leaves or in the shadows of the plants. After you've carefully planted your green friends into the aquarium, you'll need to fertilize the substrate. This is done with root tabs, which are like a vitamin pill you push into the substrate near the plant roots. One root tab will feed a 5" x 5" area. Depending on how many, and what types of plants you have, root tabs should be replaced every 4-6 months. We recommend Seachem Flourish Tabs as they are specifically designed for aquarium use and are safe for fish.

— Beginner Plants

There a vast number of aquatic plants available for your freshwater aquarium. As you become more experienced in maintaining an aquarium, you will want to discover and experiment with different types of plants. That said, here are our top 3 picks to get started:

Elodea (also called Anacharis) An rich, green plant with a long stem. Small green leaves cover the entire length of the stem.

Anubias A flowering plant with strong roots and thick, hardy leaves. It grows well even in low light conditions.

Amazon Sword A bushy plant with a short stem. The long, bladelike leaves will provide inviting hiding spots for your fish.



— Attaching Plants

If you want to maximize the immersiveness of your aquarium, you can attach plants to driftwood and rocks in addition to planting them in the substrate. The traditional way to do this involves tying the plant to the decor with black thread. When done correctly, the plant will grow and attach itself before the thread disintegrates. Alternatively, you can use a couple dabs of super glue gel to ensure the plant is forever bonded to the decor. Make sure the glue cured before putting the decor back into the aquarium.

Driftwood

Other than plants, driftwood is the best addition to your aquarium to give it a rich, depthful appearance. As its one step closer to an authentic, natural environment, it will reduce fish stress. They'll enjoy the additional hiding spots. It also encourages curiosity as they'll inspect it for uneaten food. You can certainly use any driftwood you find in your local streams or ponds in your aquarium. However, there are few things to consider. First, the wood may not sink. It takes time for wood to become water logged. You can speed up the process by boiling the wood or otherwise keeping it submerged in a bucket until it does sink. Second, any wood taken from nature will have organisms living in it, including bacteria, fungus, and possibly snails. If you don't want to risk introducing these organisms into your aquarium, its best to boil the wood. Alternatively, you can soak it in a bleach solution (2 cups per gallon of water), then rinse and let dry. Use a soft brush to remove loose debris from the driftwood before placing it in the aquarium.

The easier way to procure driftwood is to simply purchase a high quality piece (try eBay). Depending on where you live, the purchased variety are often more spindly and ganglier than what you'll find your local environment.

— White Fuzz

After introducing driftwood into your aquarium, there is a chance that white fuzz will grow on it and maybe even spread to other areas of the tank. This is temporary and will go away without intervention. It will not harm your fish.

— Tannins

Tannins are biomolecules that are released from decaying wood and plant matter. After introducing driftwood into your aquarium, you may notice the water color turn somewhat yellow or brown. This is caused by tannins. The tannins are harmless to your fish and with regular water changes the tannins will be removed and your water return to its normal clarity. Use carbon in your filter if you want to speed up the process.

Rocks

Rocks of all shapes and sizes can be used in your aquarium. One or two large pieces will make a statement. Like driftwood, you can use rocks from your local environment but you need to do 2 things. First, take a dry rock and pour a little vinegar on it. If the vinegar fizzes it means the rock contains calcite. Calcite is not harmful by itself, but it can change the pH level of your aquarium water, which can be harmful (moreso if the pH changes rapidly). Once you've tested the rock and decided to use it, scrub it clean under hot water to remove any debris. As with driftwood, the easiest way to obtain fascinating decor rock is via purchase. That's not to say your local environment doesn't have beautiful stone. Getting out in nature is always encouraged!

Fish

A typical aquarium will feature a mix of schooling fish and community fish. Schooling fish must be kept in groups of 3 minimum or the fish will become stressed and display unusual behavior. Some schooling fish have a minimum group size of 5 or 6, so be sure to check. Community fish are fish that don't need to be in groups, and they also play nice with other fish. When researching schooling and community fish for your tank, the first thing to do is find out the appropriate tank size for the particular species you are interested in. There are many lovely fish that would appear to be at home in a 10 or 20 gallon tank, but they actually require a 29 or 55 gallon tank. Once you find some fish compatible with your tank, you need to consider the adult length of the fish. There is a well-known rule of one inch of fish per gallon of water . It's not a perfect rule, but when followed, it ensures that your fish will have swimming room, and that the filter can handle the amount of waste the fish produce. You can break the rule a little if some of the fish tend to occupy a certain part of the tank. For example, plecos almost always stay on the bottom or sides of the aquarium, so they won't take up much swimming room.

Your tank may be overpopulated if the ammonia level is consistently over 0 ppm.

— Beginner Fish

Danio A curious, zippy schooling fish.

Betta An elegant, independent community fish.

Corydoras An active, bottom-feeder schooling fish.



— Snails

Snails can be an interesting addition to any freshwater aquarium. Certain snails, like the Ramshorn snail or Mystery snail, can be quite eye-catching. Many aquarists simply like snails because they are part of the natural ecosystem. They fulfill a helpful role in consuming aglea, decaying plants, and other organic wastes. Unless you despise the look of them, there's no real downside to having snails. In the worst case, they will multiply quickly and you'll have to remove some to keep your tank looking nice.

— Treating Ich (Ick)

Many aquarium owners encounter ich (pronounced 'ick') during their tenure. Ich is an external parasite that shows up as small white dots on your fish. Left untreated, it has a high chance of killing the infected fish. It is also contagious and can kill every fish in the tank if ignored, so act quickly. The first thing to do if you have a case of ich is make sure the water temperature is correct and ammonia levels are 0 ppm. If one of these is not right, the fish may have been stressed and became susceptible to infection. The easiest way to treat ich is with Tetra Ick Guard. Remove any carbon in your filter before using medication because the carbon will absorb the medicine. To treat ich naturally, you can dust the fish food with ground ginger, which is known to have antimicrobial properties. Do this at every feeding until the ich goes away.

Maintenance

It is recommended to do a 25% water change every two to four weeks. Many aquarists also have great success with a monthly 1/3 (33%) water change. To do a water change, turn off the filter and remove the correct amount of water using a pump siphon. Siphons double as a substrate cleaner. If you are using gravel, the siphon opening can be pushed into the gravel to suck up any debris. If you are using sand, you will want to keep the siphon opening slightly above the sand so that only debris gets removed and not the sand. Before beginning the water change is also a good time to clear the glass with an algae scraper or razor blade. That way any free floating algae may get removed with the water change. Due to evaporation you may need to top off your aquarium occasionally. Add water until the water line touches the bottom of the black rim. Always make sure tap water is conditioned first! Ensure any water you add to the tank is at least at room temperature or warmer before adding it to the aquarium.

The last thing you should consider to be a responsible aquarium owner is testing for ammonia. We recommend API Ammonia Test Kit as it provides fast, accurate results and you get over 100 tests with one kit. We encourage at least monthly testing to ensure your filtration is consuming all of the ammonia. Remember to avoid overfeeding if at all possible because it will result in ammonia spikes, which can harm your fish.

FIN

We hope you found the above information useful and by this point you should have a very healthy understanding of what is involved in caring for an aquarium. Of course, there is more to learn. Please investigate some of the resources below!