Science of Freshwater Aquariums (part I)

When I decided to buy aquarium for the first time, I was pretty lost. I didn't know what to buy and why do I need it. In order to help future aquarium owners I will create my first post on one of my hobbies - aquaristics.

First off - what are the basic items needed for freshwater aquariums?

1) Aquarium - It is generally not recommended to buy bowls since it distorts fish view and is considered to be painful for fish. Bigger aquariums are usually better (although some fish species prefer smaller environments). If you opt for custom made aquarium, keep in mind that thickness of glass depends on volume of aquarium.

2) Lid with lights - In order to minimise vaporisation as well as protect ecosystem from outside, lid is needed to cover the aquarium. Lights are crucial because it provides fishes vitamin D. Different types of light are beneficial for different things - some are good for fish colouration, some are good for plant growth.

3) Filter - Fish don't always eat all of their food and they defecate in the aquarium. This produces deadly ammonia. Ammonia needs to be converted to nitrite by bacteria. Nitrite is still toxic for fish so it has to be further converted to nitrate. Nitrate is not toxic in smaller quantities and can serve as growing supplement for plants. In order to keep aquarium clean filter collects decaying matter and houses bacteria which convert it to nitrates (as final product).

4) Pump - Even though fish live in water they still need oxygen to survive. Without oxygen dissolved in water fish will suffocate. Pump has dual role - first is to stir water so more oxygen can be dissolved in water and second is to drive water through filter so it can be cleansed.

5) Heater - Not all species live in cold waters, some (e.g. Guppy) live in tropical waters. To provide stable temperature at all time is important for fish health as sudden temperature changes can lead to stress, sickness and death.

6) Thermometer - To make sure you have constant temperature in aquarium you need a thermometer.

7) Siphon - Some decay can be stuck among gravel at the bottom of the aquarium. It can be removed with a simple siphon that circulates the gravel and sucks up decaying matter.

8) Water conditioner - Tap water contains chlorine and heavy metals. This is harmful to aquarium organisms and should be removed with conditioner.

9) Bacteria starter - If you are setting up your aquarium for first time, these bacteria needs to be introduced to aquarium in order to multiply and start converting ammonia to nitrate.

10) Gravel or sand - Bottom dwellers prefer sand due to their body touching the bottom which is not as harsh as gravel.

11) Fish food - Be sure you know what your fish eats. Some eat algae, some eat meat, some are bottom dwellers, some swim in mid/top section. Take all that in consideration when buying food.

12) Net - Safest and least stressful way of handling fish is with net. This way it does not come in contact with your hands (which might have some harmful bacteria/fungi on them). For fish with delicate fins use finer nets.

13) Plants and decorations - Plants can greatly improve your ecosystem by consuming nitrate and producing oxygen. They also serve as hiding and resting places for fish. When putting decorations make sure they don't have sharp edges and that they are properly treated before introducing it to aquarium.

That is all you need to start your aquarium.