How To Start A Freshwater Aquarium

The start

So, you’ve decided to start your own fish tank. Fish keeping is a rewarding hobby but first things first. You need a tank. How do you choose?

The best advice I can give straight off the bat is to choose the biggest tank you can afford. Recently mini tanks have started to become a trend and act nothing more than a vanity piece, unless you have very specific requirements and are well researched stick to the basics.

Get an idea of how many fish you want and get an estimate of how big they will grow. Now you will need 24 square inches of surface area of the tank for everyone inch of adult fish you intend to keep. So, for example, If I have five fish that have a total of 20inches in body length then I will need at the minimum 480 inches of surface area.

As this is a beginner guide, I will recommend sticking to either a regular or long tank.

You’ve got the tank, now what? Substrate

So now you have your very own fish tank, but don’t put the fish in yet. You now need some substrate (floor).

First, we will start with substrates not to use. Do not use Sea sand as it can contain living organisms which can pollute the water. Painted gravel or glass pebbles can diffuse over time and irritate or even kill your fish.

Also, if you plan on planting real plants in your aquarium, take note that you will need two layers of substrate, the first (bottom layer) being a nutrient rich substrate (feeding your plants) followed by a second substrate (top layer) such as gravel or sand.

Common gravel

You can use bog standard aquarium gravel as a substrate, it is easily the most common type of substrate used. It can be kept clean by vacuuming quite easily.


Sand is a great substrate and can be very clean. It will over time be compacted not allowing any particles past the surface and paired with a powerful filtration system can be the perfect substrate for many aquariums.


This can be used as a great bottom layer for planted aquariums as it can naturally feed the plants over time.


Laterite much like vermiculate is a fantastic bottom layer for planted aquariums and allows the plants to feed over time.

Next? Add water

Simple, add water. Ensure to add a water conditioner such as Tetra aqua safe (insert link). Remember you need to rid the water of chlorine since it’s quite deadly to fish.

A quick tip when adding water is to pour it over something first like a plate to make sure it doesn’t disturb any gravel when being sploshed in.

Add the air pump

Aquariums can be successful without an air pump but, it makes it easier for the beginner if you purchase one. When selecting an air pump ensure to purchase one that is slightly larger than you think you will need. Check out our selection of air pumps below.

Purchase a filter

Ensure to select a filter with the correct capacities for your tank check out ourtop fish tank filter reviews (2019) for recommendations and more information on how they work.

Time for cycling and fish!

Now you have the basics set up, you can obviously install decorations such as rocks or plants to your tank and it is recommended depending on the fish you select natural habitats.

It can be difficult to pick fish that will live peacefully together and not try to hurt each other.

The best types of fish to first get into the tank are hardy fish that can survive a range of elements and are known as ‘tank cycling fish’.

These are fish like, Cherry or Tiger Barbs, Tetras, Guppies or Gourami’s.

Ensure to not over feed the fish during the early cycling of the tank, every few days ensure to replace around 15%-25% of the tanks water.


Now you have your fish and they seem to be getting on swimmingly, its time to start monitoring the toxin levels in the water. You can buy commercially available kits such as the ones listed below. The toxins in the water need to reach near zero before you can add any more fish.

The results you are looking for is ammonia below 0.5mg/L and nitrite below 1mg/L.

If for any reason the tests reveal that these are trending towards unsafe levels, ensure to change the water more frequently.


You now have a beautiful tank that you can keep for many years, ensure to keep testing and maintaining the tank regular and your fish will live happy and long lives.

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