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What’s inside your aquarium?

An aquarium is a home-from-home for pet fish; with a bit of imagination and time, it can become an underwater world which lets you enjoy fish and aquatic life in your home.

Fish keeping is an incredibly fascinating and rewarding pastime made possible by your aquarium.

But you need more than just an aquarium – the bits inside are the parts you really need to understand. Let’s get to know them in a little more detail:

The filter keeps the whole aquarium moving; it physically cycles the water around the tank.

A filter is the sewer treatment works of the aquarium; it uses foams and floss to physically remove large pieces of waste from the water, and grows good bacteria that process toxic waste chemicals into safer components. In most examples, the filter is a box that sits in or just outside the aquarium.

Inside the filter is a pump that pushes water through filter media such as foams, floss and ceramic media (the home to the good bacteria), and out the other side to re-enter the aquarium. Filters come in lots of different shapes and sizes for different aquariums but one thing’s for sure: every aquarium should have one. Find out more about your filter in this article.

Light is essential for a thriving aquarium. Well controlled, specialist aquarium lighting will provide the right type of light to help plants grow, fish thrive, and keep algae at bay.

Lighting can come from traditional bulbs, or LEDs. LEDs are the more efficient of the options, but both do a good job depending on the needs of your tank.

It’s important to control your aquarium lighting to mimic a natural cycle. Too much light will make your tank turn green with algae, and too little will leave you with dull looking fish and dying plants. Try a ten-hours-on and fourteen-hours-off routine, or use a timing device that can automate this.

If you keep fish from tropical waters, you’ll need a heater. So many popular aquarium fish come from warmer parts of the world, making an aquarium heater essential.

There are lots of different types of heaters to choose from. The most common heaters are thermostatically controlled, sealed glass tubes that contain an element. They’re often pre-set with a particular temperature, but tend to have a thermostatic controller which lets you set the temperature yourself. Fit the heater by following the manufacturer’s instructions, and be sure to use a thermometer to double check the heater is working properly.

Another type of aquarium heater available is a flat heater that’s programmed to maintain a set temperature above the ambient temperature. They constantly produce a set amount of heat, so the water temperature should be carefully monitored in warm weather. These heaters can be quite flexible and can be fitted into the aquarium in several ways. You can hang the heater on the side of the aquarium, tuck it away in the filter (depending on the aquarium design) or bury it in the gravel.

You can also add air pumpsair stones and air ornaments. They do more than look pretty; they add extra air to your aquarium, benefitting the fish and plants with extra oxygen.

Oxygen is naturally scarce in water but required by the fish, so circulating the water with an air pump helps take oxygen into the water from the surface and drives out poisonous carbon dioxide. A filter helps circulate water in an aquarium, but the best way to ensure optimal gaseous exchange is to use an air pump and air stone.

Gravel, also known as substrate, is the material on the base of your aquarium. There’s a huge variety of substrates to choose from. It comes in many shape, sizes – from almost sand to stones – and a variety of colours.

Substrates can also be artificial, with a variety of brightly coloured option available. Gravel does more than look good. It also anchors ornaments and plants, and holds nutrients to feed live plants.

No matter what you prefer, make sure you use only specialist aquatics gravel and thoroughly wash it in plain water before you add it to your aquarium.

You will also probably want to add fishplants and decorations to your aquarium to complete the look.


Why do I need to put gravel in a fish tank?

Gravel is a great addition to any fish tank as it helps to create a natural environment for your fish. It provides hiding places for fish, especially those that like to burrow, and it offers enrichment for bottom-dwelling fish that enjoy foraging through the substrate for food. Additionally, it helps to reduce reflections in the tank, which can cause stress to the fish.

Do I need to clean the gravel in my aquarium?

You should regularly clean the gravel in your aquarium. Gravel can become dirty with food, waste and other debris over time. If left uncleaned, it can lead to a build-up of toxic substances in the water which can be harmful to your fish.

To clean the gravel, use a gravel vacuum that comes with a special nozzle. Start at the furthest corner of your tank and work your way out, using quick, short strokes to suck up debris.

How to clean algae off my fish tank gravel?

It is recommended that all aquarium owners use a gravel vacuum regularly to remove debris and detritus from the substrate. This process involves turning over the gravel substrate, which deprives it of light and helps kill algae.

Additionally, using a gravel vacuum helps eliminate debris from the gravel that can act as nutrients for algae growth.

When cleaning a fish tank, should you remove the fish?

When cleaning a fish tank, you should not remove the fish. Removing the fish from their environment can be stressful and even fatal for them. Instead, clean the tank while they are still inside.

Clean gradually over the course of several days, rather than all at once. This ensures that the water conditions remain stable and minimises stress on the fish.

Why will my filter not suck up excess waste in my aquarium?

If your filter is not sucking up excess waste in your aquarium, there are a couple of things you may want to check.

Check that the filter intake tube is submerged correctly in the water and that there are no blockages preventing water from entering the tube. Also, ensure that the impeller (which powers the filter) is working correctly and has not been damaged or blocked by debris.

If you have a tank with a canister filter and there is still excess waste on the bottom, I would recommend adding a small internal filter or a wave maker to help bring that waste closer to the filter inlet.

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