Tropical Fish and Aquariums – A Beginner’s Guide

Fish come in all shapes and sizes and can have some entertaining habits. They are not as expensive or demanding as other pets such as dogs or cats but still need to be treated appropriately and given the correct amount of care and love. Tropical fish have a stunning array of colours and species and to get the best from them you need to know how to care for them.

What do Tropical fish need?

Firstly, they obviously need a tank. Along with a tank they need lighting, heat and filtration. They also need water, as obvious as this sounds, water is hugely important and the key to maintaining your fish is maintaining the water. Aside from that, there is not a lot else, except the right environment for your chosen species.

In this guide we will be looking at creating a beginners tank. In the hobby this sort of set up is referred to as a ‘community tank’, which means it contains a variety of easy to keep aquatic animals that get along well and have similar, not specialist, requirements. Many hobbyists that have huge amounts of experience still keep these sorts of tanks, mainly because they are so attractive and fun.

What tank?

Firstly you need the tank, generally speaking bigger is better, as smaller tanks are harder to maintain and some just aren’t big enough for the fish. However you must evaluate your space and budget, a medium sized tank of around 40 to 60 litres is adequate, but it shouldn’t be smaller than this.

Some tanks come with a full light unit, heater, filtration system and even a stand or cabinet. It’s up to you if you go for these set ups, it is somewhat helpful to have a built in light, heater and filter, but these are bought separately very easily. Because of this it is fine to buy just the tank, although you will need a cover or lid and sometimes it is more cost effective to buy the complete set up as a ‘starter kit’.

Where you position your tank after purchase is very important too. It shouldn’t be in direct sunlight as algae problems could occur. It also shouldn’t be near windows, radiators or anything that may affect the temperature of the water.

Providing Heat

Tropical fish differ from cold-water fish, as they need higher temperatures to live in. This also means that they can be more sensitive to temperature changes. A heater for tropical fish is the best way to provide the correct temperature as many have thermostats that will measure the temperature of the water and adjust themselves accordingly. Of course, you still need to keep an eye on the temperature with the help of an aquarium thermometer, which can be stuck onto the tank or floated inside. Temperatures vary from species to species but a good mod ground for beginner species is 23 Celsius centigrade to 26 Celsius.

Providing light

Tropical fish also benefit from a light source, for how long it is left on varies for species but a good guide for beginner fish species is 10-12 hours a day. If your tank has a light prefitted there is very little setting up to do. If not then you need to first purchase a starter, which is the fitting a light tube goes into and is powered by. It is generally easier and neater to have a tank with one built in, but it is easier to fix if it is separate. Most starters come with holders for the tube, which can be fixed onto the lid of your tank.

When choosing the bulb buy one that either fits the tank (prefitted ones have bulbs manufactured especially for the tank) or buy one that fits the diameter of the fitment, which is usually an inch or one and a half inches (you might want to make a record). Also, obviously chose the correct length for your tank!

Lights have different spectrums, as a beginner you don’t need to worry too much, you just need to know that lights with more ‘blue light’ will provide a stronger light than those with more ‘red light’. Blue light is often used for plant growth (and algae growth!) and red light is used to show off the fishes colours, both are usually used with a balanced or ‘white’ light, which is the only sort of light you should be aiming for at the moment as it will provide the best of both worlds with little problems.


Filtration is the most important aspect, aside from water, as it is what helps keep your fish healthy. It removes waste and toxins from the water and the sponge harbours helpful bacteria that keep the balance in the tank. The movement created also increases the surface area of the water and allows more oxygen to enter the water.

Some set ups have built in units for filtration, if not you can very easily buy a unit that will either stick or slot into your tank. The filter itself consists of a plastic casing with a little motor inside that draws water in through a sponge and then pushing it out of a nozzle at the top. You will need to get a filter big enough for your tank. It should be positioned so that the nozzle sits level with the water surface and so it can easily be connected to a power supply.


The most important part of the tank, more than you would realise. Not only would your fish die if it wasn’t there but if it isn’t the right sort of water your fish could be at risk. Firstly, it must be clean water; this is to prevent build-ups of nitrates in the fish tank, which can burn the mucus membrane on your fish. However, for the same reason you shouldn’t use chlorinated water, like that out of your tap. You can use tap water, but only if it is left to mature for a day or treated with a chemical preparation to remove the chlorine.

You also need to consider the hardness and softness of the water. Different types of fish like different types of water. Most beginner’s fish will tolerate both but it is worth keeping in mind the type of water you have in case you want to try different species later.

The PH of the water is extremely important. You can buy PH testing kits for fish tanks to easily find out what sort of water you have. Some advanced species have very specific PH that they prefer but as a general rule, getting the PH near to 7.0 is good, although being around 6.8 to 7.5 is fine. If your PH is out of this zone you can buy PH increasers, decreases and stabilizers to rectify this. Make sure when you test regularly and with all the décor in as things such as waste levels, décor and even foods can change the PH level.

Décor in the tank

The décor in the tank is important as it recreates your fish’s natural habitat allowing them to exhibit natural behaviour. Some décor items have other purposes, for example gravel which helps trap debris and makes a nice base for other décor.

The gravel shouldn’t be too rough or sharp and it shouldn’t be small enough to clog up filters or be swallowed, natural pea gravel is a good all round fish tank gravel that is good for allsorts of fish, of course the colour you choose is up to you! Just make sure to wash it thoroughly first, to remove dust that could muddy the water.

Plants should be used, although it is unwise to use live plants as a beginner. Plastic plants look very realistic and are easy to clean. Purchase a variety of types and sizes for a nice natural effect.

Other décor can include rocks, bog wood, slate, pebbles, ceramic ornaments, resin ornaments and plastic ornaments, all of which should be washed with hot water before placing in. It’s up to you what sort of style you use but make sure you choose items than fish won’t get hurt on or trapped in. Also note that more décor means less water and less fish.

You should aim to create a natural space, where fish can swim, hide, rest and carry out natural behaviour in.

Setting up your tank

When you first get your tank you should set it up without any décor. Place the filter and heater in, but do not turn them on. Fill your tank with water to about quarter, you can then add gravel, plants and any other décor you have. Make sure not to have unstable areas or areas fish could get trapped. Also do not build things around your heater, or you will have very hot and very cold areas. A good idea is to put larger plants and décor toward the back, medium toward the middle and sides and small things at the front or in the middle.

Now you have it set up, add more water. You can use a flat piece of slate or an old saucer to pour the water onto so it does not disturb the décor you have used. Fill it to about an inch and a half from the top.

You can now switch on the heater and filter. You should also switch on the light and keep it running as if you had fish in there. It is very important not to add fish at this stage. The reason is that your tank is new and does not have any bacteria in the water or filter sponge. During the next few days the tank will undergo some changes referred to as ‘cycling the tank.’ This is dangerous for the fish to be in and will result in deaths.

Instead run the tank for a week or two as if you had fish in there, turning the light on and occasionally adding some food (although not regularly as if you had fish as none of it will get eaten this time!) This allows the tank to settle and provides a safe environment for your new pets.

What do fish eat?

There are lots of things fish will eat, although the most convenient food is the flake food. You should buy a tropical flake food, as it will provide all the nutrients that your fish need.

Some fish will enjoy bloodworm, tubifex and brine shrimp as an occasional snack. These can be bought in frozen tablets or freeze-dried blocks, to give as a treat.

Selecting the fish

Now you have your tank set up you can go and purchase your fish. You should only purchase 6-8 fish at a time to avoid unbalancing the water in the tank. You should also ask for advice on how many fish you can ultimately stock in your tank, with regards to the size of your tank and amount of décor you have.

Some good species for a community tank include; Guppies, Zebra danio, platies, mollies, small species of gourami, small loaches, tiger barb, cherry barb, neon tetra, cardinal tetra, lemon tetra, Mountain minnow and swordtails.

It is best to research these fish first, as although they should all be fairly compatible it is best to know what they are like and if you like the way they will behave in your tank.

Buying and bringing your fish home

As mentioned earlier, you need to introduce fish gradually. Start by buying a few (no more than 8) small middle feeder fish. This could be tetras, guppies, barbs or danio. When selecting the fish look for specimens that look shiny, active, have no abnormal lumps or behaviour and are free of abnormal marks. If you see dead fish in the tank or notice any of these problems it is best to choose a different supplier.

After you have brought your fish home, you should wait at least a week until you introduce more fish. You should aim to introduce fish that feed on the surface and that will swim around in shoals or in the open first and the fish that like to dwell on the bottom, eating debris last.

Introducing your fish is a simple process, however it must not be rushed. Fish who have just been purchased are often stressed and this makes them vulnerable. Fish are also susceptible to changes in their water and temperature so this must be managed when relocating your new pets. Firstly, you should turn the light on your aquarium off. This will reduce stress. You should place the bag your fish are in, unopened, in the water. You can peg it to the side of the tank if it floats around or goes to close to the filter. This stage will ensure the temperatures equalise in the tank and the bagged water, allowing your fish to gently acclimatise, you should keep the bag like this for around 20 to 30 minutes.

Next you should open the bag and (with it secured to the side) put some water from the tank into the bag. Doing this will allow the fish to get used to any differences in the water’s PH, you should wait another ten minutes before un pegging the bag and allowing it to fill and mix with the aquarium water. You should allow the fish to swim free, do not pour them, as this will stress your fish. You can however use a fish net to gently coax them out. Take out the bag and keep the lights off for at least an hour, allowing your fish to explore and feel safe. They will likely hide to begin with, but this is natural and in time they will feel safe. Do not feed them until the next day.