How to set up an Aquarium


I have my fish, now how do I set up my aquarium?

In this article, we will explain how to set up an aquarium including: preparing the substrate, preparing the tank, preparing the water, installing equipment, cycling the tank and how to add fish in a way that will minimize losses.

Setting up your aquarium may only take an afternoon however adding fish should follow the one-to-two-week aquarium cycling process. To ensure the highest survival potential you should add only a few fish at a time to stabilize the ecosystem and allow for healthy bacteria to adjust to the growing occupancy.

The aquarium setup steps are outlined as follows:

  1. Set up the aquarium and stand
  2. Wash and add substrate/gravel and clean water
  3. Install heater, water temperature sensor and display, water and UV filter, lighting and air stone
  4. Add decorations
  5. Cycle your aquarium
  6. Add fish

The recommended materials needed to set up an aquarium are as follows:

  • Aquarium
  • Aquarium lid
  • Aquarium gloves
  • Surge protector power strip
  • Heater
  • Filter
  • Air stones
  • Air pump
  • Air tubing, tubing connectors, tubing one-way valves and 4-way control and check valve
  • Ultra Violet Filter
  • Lighting
  • Substrate
  • Decorations
  • Water dechlorinates
  • Aquarium water test kit
  • Aquarium water syphon / gravel cleaner
  • Bucket
  • Fish food

Detailed step by step instructions for setting up an aquarium..

  1. Set up the aquarium and stand

Find the ideal location for your fish tank.

Location, location, location
  • The area should be on a flat waterproof hard surface.
  • The area should allow for at least 6 inches (or 15 mm) from the sides and back to ensure there is enough room for equipment and access.
  • The aquarium water should be maintained at a stable temperature so avoid a location that is in direct sunlight or next to the air conditioner
  • Avoid an area that is next to flashing TV screens, loudspeakers or high traffic areas. From the fish perspective these influences are stressful and can cause fish to become sick, shorten their live span and even cause death.
  • Make sure the area you place your aquarium can handle the weight of your aquarium with water. Water weighs 8.3 pounds per gallon or 1-liter weighs 1 kilogram.
  • The location should be reasonably close to a water source and drain as regular maintenance will require partial water changes.
  • Add background to fish tank by cutting to size then taping along the edges of the background to the tank

For more helpful information on selecting the best location for your fish tank please see our article Where to Place a Fish Tank in Your Home.

  1. Wash and add substrate/gravel and clean water
  • The fish that you select should guide what kind of substrate you use. Some fish like knifefish, eels, goby and rays prefer a sandy bottom. Sand requires more frequent bottom cleaning. This is because the sand doesn’t allow water flow through it which causes harmful anerobic bacteria to grow and produce harmful compounds. Regular monthly cleaning will prevent this potential issue.
  • Fish like cherry shrimp, plecos and several species of algae fish prefer gravel. Most freshwater aquariums are best suited for pea sized gravel or crushed coral. The size of the gravel allows for water for flow through the substrate. The added oxygen maintains a higher ratio of good bacteria to bad.
  • The best aquarium gravel to start with is CFKJ River Rock, Seachem Flourite Black Clay Gravel or Carib Sea Crushed Coral.
  1. Install heater, water temperature sensor and display, water and UV filter, lighting and air stone.
  • Research the ideal temperature for the fish you will be adding to your aquarium. Add the heater to the inside of your aquarium and set the temperature. Add the water temperature sensor and wait 24 hours to see what the stable water temperature is on the display before making further adjustments.
  • Assemble then add the water filter to the aquarium. If your aquarium stand and tank are on a surface that is not watertight, like wooden floors or carpet then use a submersible water filter rather than an external water filter that hangs on the outside of the tank. Submersible water filters do take a little more room in your aquarium, but you never have to worry about potential leaks or spills.
  • If your aquarium stand and tank are on a watertight surface like concrete or tile, then you can free up more space in your aquarium for fish and live plants by using an external water filter. We prefer canister water filters over power filters that hang on the back of the tank as there is less water evaporation and more safety features from leaks.
  • Assemble then add the aquarium Ultra-Violet (UV) sterilizer. UV light sterilization is an effective way to reduce disease outbreaks in your aquarium. Most bacteria, viruses, and parasites are killed before they can infect your fish. In addition, UV sterilizers keep your aquarium clear by reducing the presence of free-floating microalgae in your aquarium.
  • There are UV filter options like stand-a-lone units with adjustable flow rate pumps, canister water filters with integrated UV lights or inline UV filters that can be added to the canister filter inline tubing.
  • The longer the tank water is exposed to the UV light the greater its effect on algae, bacteria and parasites. The stronger the UV light wattage the greater its affect as well. A 9-watt to 15-watt UV bulb is ideal for aquariums with an average life of about 6 months between replacements running 2 to 4 hours per day.
  • Add your aquarium light to your tank. There are three primary types of lighting in use for aquariums today, they are LED, T5 or T8 florescent and metal halides. LED dominates the market due to its low cost, low energy consumption and light spectrum diversity. The best aquarium lights are programable to simulate sunrise, noon daylight and evening light automatically. If you have live plants, then full spectrum LED lighting is essential.
  • Connect your air stone and air pump outside the tank to airline tubing. Add a one-way check valve to your airline tubing to prevent water from siphoning out of your aquarium and damaging your air pump. Now add your aquarium air stones to the inside of your tank and attach suction cups to the tubing to keep it from floating to the surface.
  • If you are adding multiple air stones to your aquarium, consider upgrading your air pump to handle greater airflow and using a 4-way air control and check valve to manage the air flow of each tube.
  • The bubbles produced by air stones gradually fill your aquarium with oxygen and circulate the water. Live plants need CO2 to thrive and air stones will create equilibrium with atmospheric CO2 throughout the aquarium. Plus, many of your fish will enjoy playing in the bubbles.
  • Do not use soap, detergents or chlorine as they are highly toxic to fish
  • To wash substrate/gravel, put into a strainer or colander over a bucket and run water. Stir the gravel to remove debris, drain the water and repeat until the water becomes clear, then add to aquarium.
  • The substrate/gravel should cover the bottom of your aquarium to approximately 2 to 3 inches or 6 centimeters deep.
  • When adding water, it is best to filter or clean the water using a reverse osmosis filtration system. If this is not an option and municipal tap water is used, then chemically dichlorination is essential to prepare the water for living plants and animals.
  1. Add Decorations

Ideally arrange decorations that will hide your equipment and give your fish places to hide. The first fish in your tank will claim the best spots so gradually add your decorations as you gradually add your fish to your aquarium to give new occupants a place of their own.

Avoid sharp objects, plastics that have been painted (many of these contain toxic heavy metals), concrete, ceramics, coins or copper. Wooden decorations like driftwood can be beautiful but will leach tannic acid into the water over time which can be stressful to fish who prefer alkaline conditions.

You can avoid this potential problem by boiling the driftwood in a pot of water to quickly release the tannins before placing it into your aquarium. You may need to repeat this process with a fresh pot of clean water until the water remains clear after boiling.

Live plants do wonders for the bio-chemical balance, beauty and overall health of your aquarium. Plants consume waste by-products, use nitrogen and CO2 (carbon dioxide) and produce 02 (oxygen) in exchange. Use quality aquarium safe plant food weekly and after water changes and make sure the water is warm enough for them.

If you choose gravel for your aquarium substrate you may want to consider live plants instead of artificial plants. For more helpful information on how to get started please see our article, Can Fish Tank Plants Grow in Gravel.

  • First wash your decorations in clean water to remove any debris or dust particles. Do not use any detergents, Clorox or ammonia as these are toxic to you fish and live plants.
  • Position your tallest decorations in the back of the tank first then work your way forward
  1. Cycle your aquarium

The nitrogen cycle is Nature’s way of breaking down waste produced by your fish and converting them into essential nutrients. The nitrogen cycle gradually creates enough beneficial bacteria to do this important job for the size of your tank, the number of fish, plants and waste materials produced. “Cycling” refers to the conversion of the waste by-product ammonia to nitrite to nitrate.

Ultimately the reason you need to cycle your fish tank is so that the beneficial bacteria can colonize to the point that they can eat the harmful ammonia and nitrites as quickly as they produced. This will protect your fish and keep them alive and happy.

A new fish tank doesn’t have the essential ecosystem needed to manage and sustain life until you create it. It takes an average of 3 to 6 weeks to form the good bacteria through the Nitrogen cycle process.

3 to 6 weeks sounds like a long time to wait before adding fish. The good news is that there are ways to jump start the nitrogen cycle that can cut the time in half. Read the article “How Long Do You Have to Wait to Add Fish to A New Tank” for the details.

There are three methods for cycling your fish tank. The fish-in cycle, the fish-less cycle and “seeding” your fish tank.

  1. The Fish-in cycle

Add fish at a rate of 2 or 3 per week to safely allow the bacteria to adapt to the new bio-load and not be overwhelmed. As you slowly add fish your good bacteria will adapt and multiply to meet the needs of your growing ecosystem.

If you add too many fish too fast you risk their waste production being higher than the bacteria in your tank can keep up with. When that happens ammonia (a by-product of fish waste) will spike. Ammonia is toxic to fish and many new owners make this mistake only to discover it after many if not all of your overloaded fish end up dying.

Adding 2 or 3 fish at a time will create slightly more waste which in turn encourages the gradual growth of more good nitrifying bacteria. This approach keeps the ammonia and nitrate levels low enough to do no harm to the life in your aquarium but still high enough to feed your cultured bacteria so they don’t starve.

Continue this process until you have reached your planned occupancy for your aquarium.

  1. The Fish-less cycle

Step 1: Getting the Ammonia Started

Your aquarium environment should start producing ammonia. To start this process, drop a few flakes of fish food into your tank and follow this pattern every 12 hours. Each time you do this the amount should be the same as a single fish feeding for your future occupants. The flakes will begin to decay and release ammonia into your tank.

Step 2: Testing for Ammonia

Be prepared to use a test kit and monitor the ammonia levels in your tank every few days. The goal is to maintain the ammonia levels at least 3ppm (parts per million). If the levels are below this, then add more flakes and let them decay. Bacteria called Nitrosomonas will begin to grow and start consuming the ammonia. You should replenish them by adding more flakes whenever it drops below 3ppm. At the end of the week, you should be ready for the next step.

Step 3: Testing for Nitrites

Your first week is finished and it is time to test for nitrites. Be prepared to use a commercial test kit for this step. The presence of nitrites in your tank will let you know the cycle has started. Keep the cycle going by continuing to add ammonia as you have done in step 1 for two to three more weeks.

One word of caution. If your nitrate reading ever gets above 40, you’ll need to do a water change to bring this number down. Aim to do 10-25% water changes every 2 to 3 days. Anymore, and you’ll risk removing the ammonia and nitrite that beneficial bacteria need to feed on.

Step 4: Testing for Nitrates

You have been testing for ammonia and nitrite levels every other day or so for a few weeks.  When you see the nitrite, levels start to drop it is time to start testing for nitrates. The presence of nitrates indicates the cycle is nearly completed. Keep testing the waters every other day or so and when the ammonia and nitrite levels have returned to zero, the cycle is complete.

For more information on recommended water testing solutions and step by step instructions, please see our article on How to Test the Water in an Aquarium.

PRO TIP: “Seeding” will speed up cycling your fish tank

You know about the 3-6-week time period for growing beneficial colonies through the nitrogen cycle. But what if there were a way to reduce that by as much as half the time it would normally take? There is a way, and it is called “seeding”.

Here is how it works, after your tank is first set up you “seed” the aquatic environment with good bacteria taken from an already established aquarium. Pre-established good bacteria can come from a used sponge filter or filter pad rinsed in tank water, a handful of bacteria populated gravel or substrate, or even an external filter box.

Seeding can be done as a first step to the fish-in cycle or the fish-less cycle to cut the fish tank cycling process time down.

Seeding your aquarium can enable you to safely stock more fish in the new tank sooner. If you don’t have another established aquarium, then look to some other potential sources for your seed stock:

  • Friends – If your friend has an established aquarium simply ask for some gravel or substrate.
  • Local Fish Store – Most reputable fish stores are very willing to share seed stock.
  • Local Fish Farms – Most fish farms are willing to provide samples of their rapidly changing filter media for your first seed stock
  • Fish Clubs – All fish clubs should be willing partners to help new starter tanks become established

Now take one or two cups of the seed material and hang it in mesh bag in your filter (if possible) or lay it over the top of the gravel in the new tank.

  1. Add fish

Not all freshwater fish can live in the same tank together. The best fish to start a freshwater tank are low maintenance, resilient, beautiful and thrive amongst other fish species. You want fish that are fun to watch, colorful, with interesting personalities and behaviors and non-aggressive to each other.

Adding a few fish at a time will allow the established good bacteria to adjust to the new bio-load. Waiting a week between new fish additions is a great strategy for success. For the best guidance on how and when to add fish to your new tank please see our article, Do You Have to Wait to Add Fish to a New Tank.

If you need help to know how many fish per gallon of water is ideal for your aquarium, then read our article What is a Good Size Fish Tank for a Beginner for more help.

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