History
Freshwater fish keeping dates back to ancient Egypt with depictions of captive fish “pets” being found in Egyptian writings. Modern fish keeping has evolved to become a great hobby that has been simplified by some advanced equipment.

A nicely stocked Freshwater Community Style Aquarium.

Table of Contents Freshwater Community Aquarium Geography Equipment Habitat Water Chemistry Setup Species Feeding Maintenance Books

A freshwater community aquarium seems to be a popular first choice amongst new aquarium hobbyists. These style aquariums allow you to keep a large number of different fish making it a great choice if you want to keep a “fish tank”.

There are many different places in the world to choose fish from. You could recreate an East Asia stream, South American River or an Africa Rift lake. Aqua Buys recommends replicating these environments as closely as possible. The recreation of an aquatic ecosystem in another part of the world makes for great conversation when someone asks about your aquarium and will increase your enjoyment of the aquarium hobby.

You don’t have to choose your fish this way. You could choose the fish that appeal to you. Always check compatibility (is this fish a bully?) and choose fish that like similar water conditions especially pH and temperature.

Aquarium
If this will be your first aquarium I would recommend getting at least a 20 gallon system. Smaller aquariums while appealing require more routine maintenance. If you are not used to doing weekly water changes, testing water chemistry and other aquarium tasks then a larger tank gives a beginner “more room for error”. A 20 gallon aquarium will also help quench that immediate desire that we all feel after we set up our first (small) aquarium …”I want a bigger tank”.

SeaClear 20 Gallon

Filtration
With a community of hungry, messy fish proper filtration is important. Good water circulation with a mechanical, chemical and biological filter is needed to maintain water quality between water changes. A good circulation rate would be from 4-5 times the total aquarium volume per hour. On a 20 gallon aquarium you will need about 80-100 gallons per hour of circulation through your filter. A little more than this would not hurt if you plan to fully stock your aquarium with fish.

Aqua Clear 30 (150) Power Filter

Lighting
If you plan to keep fish and no live plants your lights will only need to equal about 1 watt of light per gallon of your aquarium. If you are planning on live plants (recommended) then you will need about 2-3 watts of light per gallon. 6700K broad spectrum lamps are great for freshwater as this closely resembles the natural sunlight spectrum. The newer T5 light fixtures offer great performance and value.

24" Nova x2 T5HO Freshwater Fixture

Heating
Maintaining water temperature at a consistent level reduces stress on your aquarium pets. A good rule of thumb for selecting aquarium heaters is to have about 5 watts per gallon.

Stealth 100 Watt Heater

Other Equipment
Keep an eye on your aquarium temperature with a digital thermometer.

Digital Thermometer

Habitat

Successfully keeping a community of fishes requires a basic understanding of the animals you plan to keep. Knowing fish compatibility is also important. Setting up the right environment and water conditions for a certain group of fishes insures a higher level of success.

Most freshwater fish will do well with a simple environment of gravel substrate, some rocks, driftwood and some live plants. Some good basic plants:

Java Fern (Microsorum pteropus)
Wisteria (Hygrophila difformis)

Substrate
Using natural, small pebble gravel of a medium color is a good choice for a freshwater community aquarium. This renders better fish colors than lighter gravel and gives a natural look to the aquarium.

If you plan to add live plants to your aquarium you may want to add some Laterite to your gravel to increase the richness of your substrate. Laterite provides fertilizer directly to rooted plants. Add about 1 to 1.5 oz of Laterite per gallon.

Laterite Plant Substrate 20 oz

Water Chemistry

There are a large variety of conditions that freshwater tropical fish inhabit. The South American Streams and Rivers are about 81 degrees, pH 6.6 and KH 2-3. The Rift Lakes in Africa are 76 degrees, pH 8.1 and KH 6-9.

Most freshwater tropical fish can be kept in the following range of conditions:
Temperature: 74-82°F
PH: 6.5-7.5
KH (carbonate hardness) 3-8

Additives
If you are using tap water you will need to add a water conditioner to make the water more suitable for fish.

NovAqua Water Conditioner

Setup

This chart is a timeline describing step-by-step setup of your Freshwater Community aquarium. After the chart is an explanation of each step.

Research
Knowing what type of fish you plan to keep will make it easier to get started. Some fish have other specific requirements and will require a different setup. Check a book or search the Internet for more information on the different fishes that can be kept in aquariums.

We will recommend a few fish (see below) that look great together and are fairly easy to get started with. This will include some utility fish to help scavenge the aquarium.

Equipment and Setup
After you collect all of your equipment and decorations you can setup your aquarium. Choose a good location for your aquarium that is not in direct sunlight, has good access to an electrical outlet and will support the aquarium weight. Aquariums can weigh over 10 lbs per gallon when completely filled.

Example of a freshwater community aquarium setup.

Wet Test
Place the stand and then the tank leaving a space of at least 4”-5” for equipment behind the aquarium. Begin filling the aquarium with water. You can use buckets for most small aquariums or use a drinking water approved hose for larger setups. If you are using tap water you will need to add a water conditioner to make the water more suitable for fish.

Once the aquarium is mostly filled you can place the other equipment including the filter, heater and lighting. Don’t install any gravel or other decorations as you only are testing the aquarium and equipment. Better to find problems before you add fish.

Plug the equipment into a power strip and the into a GFCI outlet. The use of a Ground Fault Circuit can save you and your fishes from some dangerous shocks.

Turn on the filter and heater to check that everything is working. Set the heater for about 76 degrees. Use the thermometer to check the temperature. Let the equipment run for about an hour or two to make sure the heater and filter are working. After your happy with the equipment you can turn everything off and drain the aquarium an inch or so of water left.

Aquascaping
If you are planning on live plants add a layer of laterite and then add your gravel to the aquarium. You may want to rinse the gravel and laterite according to the instructions and then add the layers.

After adding your gravel you can then fill the aquarium about 1/3 and then add any plants, driftwood and other decorations. Fill the aquarium the rest of the way, plug all of the equipment back in and turn the filter and heater back on.

You can add fish as soon as the water clears up and the tank is at the right temperature. This will likely take several hours to overnight. Only add 1-2 hardy fish when you first setup.

Begin the Cycling process
After you add the first couple of fish the aquarium will start to develop beneficial filtering bacteria. This process normally takes about a month but can be shortened by using some aquarium additives including Bio-spira or Stability.

Water Changes
You may need to do some water changes the second or third week after setting up if your fish show any problems. The chemicals that can form in a new aquarium can be lethal to fish if the levels get too high. Use a test kit to test for Ammonia, Nitrite, and Nitrate. Be prepared to drain and then replace some of your aquariums water if these levels get too high. Read our article on the Nitrogen Cycle for information.

Species

Here are a couple of fish recommendations and a good scavenger. This group of fish will do well in as a small community.

Neon Tetra Paracheirodon innesi Temper: Peaceful Adult size: 1.5 in Origin: South America Feeding: Omnivore Colorful hardy fish, great in schools of 5 or more.

Neon Rainbow Fish Melanotaenia praecox Temper: Peaceful Adult size: 2 in. Origin: Asia, Australia Feeding: Omnivore A small group of 2 or 3 of these fish make a good centerpiece fish.

Corydoras Corydoras julii Temper: Peaceful Adult size: 2 1/2 in. Origin: South America Feeding: Omnivore Fun and useful cory cats do well in groups of 3 to 5. Will scavenge uneaten food.

Stocking
One method for deciding how many fish to keep uses the total water surface of the aquarium to determine stocking levels. This is based on the adult size of the freshwater fish in inches. We recommend 1 inch (body length) of fish per 12 sq. in of water surface.
Here is a reference chart for determining stocking levels based on water surface:

Another method is to base it on total aquarium volume. Recommendations of 1” of adult fish per gallon are common.
Here is a reference chart for determining stocking levels based on aquarium volume:

Fish larger than 4 inches at adult size should be kept in larger aquariums of at least 36 inches wide and 50 gallons or more.

Feeding

Feeding your fish a variety diet beyond just a can of flake food is important. Fish can develop deficiencies without the right foods. To feed your fish properly you need to know whether your fish are omnivores (plants and meat eaters), herbivores (plant eaters) or carnivores (meat eaters).

The fish mentioned earlier in the article were omnivores. Here is a good omnivore diet for tropical fish:

Flake – Ocean Nutrition Community Flake

Freeze Dried – Freeze Dried Brine Shrimp

Maintenance

Water changes
Water changes are the basis for successful aquarium keeping! This is the easiest thing you can do as an aquarium owner to maintain a healthy environment for your aquatic pets. You will need a few basic pieces of equipment including a large, clean plastic bucket, a gravel vacuum and a thermometer.

You should change about 10% (minimum) of the water in the aquarium about twice a month. A good way to remember is to do water changes on the 15th and 30th day of each month. In a 20 gallon aquarium you will change about 2 gallons.

Fill a bucket with about 2 gallons of water and treat it with water conditioner. Test the temp and adjust it to match your aquarium. Drain about two gallons from your aquarium (time for another bucket) and then pour the new treated and temp adjusted water back in.

You will need to vacuum parts of the gravel every month or two to clean up excess mess left by the fish. Take care not to plunge a gravel vacuum too deep if you have live plants.

Gravel Vacuum

Filter Maintenance
Your filter will need to be cleaned periodically. Change your carbon media every 6-8 weeks. Your mechanical media may last several months if you rinse it monthly. Rinse your sponge or filter cartridge in your old aquarium water when you do a water change. Follow the manufactures instructions for other filter maintenance.

Cleaning the Glass
Algae may grow on the inside of your aquarium on the glass. You can use an algae magnet or scraper to clean the aquarium walls on the inside.

Algae Scraper

Acrylic aquariums must be treated with special care since acrylic scratches very easily. Be sure to use cleaning devices designed for use on acrylic aquariums.

Wipe down the outside of the tank with a damp cloth (water/vinegar only) and then polish it with a dry one. Try to avoid using household cleaners and sprays around your fish aquarium.

Books

Check out some of these aquarium books for more information on fish keeping.

Mini-Atlas of Freshwater Aquarium Fishes - Axlerod

Aquarium Plant Paradise - Amano