When you first become an owner of an aquarium, it’s natural to have lots of questions – and important too if you want to be a responsible fish keeper. Are you wondering what’s the best lighting, and can I leave blue light on in a fish tank? Keep reading for answers to all your burning questions about how to keep fish, and why doing so can benefit your wellbeing.
Everything You Need to Know About Lighting Your New Fish Tank
A brightly lit aquarium is part of what makes a tank so alluring.
As part of a previous collaboration I was fortunate enough to be sent an aquarium and other required equipment to set up a tropical fish tank, and had access to an expert to get started.
I had many questions, and in particular I wanted to learn about lighting and whether I could leave a blue light on in the fish tank. After all, a brightly lit aquarium is part of what makes a tank so alluring.
In this post I’m going to go over the first steps for setting up a fish tank, the benefits of keeping fish, and a few other important questions about aquarium lights and how much light aquarium fish need.
Why Do Fish Need Aquarium Lighting?
As it turns out, artificial tank lighting is not actually an imperative for an aquarium.
The natural light entering your home is likely more than adequate for your fish.
What’s more important is that, just like us, healthy fish need a natural day / night light cycle to regulate their circadian rhythm, which in turn controls other bodily systems.
In order to thrive and avoid becoming stressed, fish require natural bright light, followed by an adequate period of darkness. However, the natural light entering your home is likely more than adequate for your fish.
The real reason to have artificial lighting in an aquarium is not for the fish at all; it’s for the aesthetic of the tank and possibly to support photosynthesis and plant growth in a planted aquarium.
Fish depend on light cycles for various behaviours.
Can I Leave Blue Light On in a Fish Tank?
There’s a myth that leaving blue light on in a fish tank is acceptable. So, Is blue light good for fish? Well, not exactly.
Blue light is known to disrupt the circadian rhythm in humans, and some of the research that led to this discovery was in fact conducted on zebra fish!
So unless you have nocturnal fish species in your aquarium, your fish will depend on light cycles for various behaviours including sleeping patterns, mating, feeding, and even levels of aggression.
Upshot: No, you should not leave any light on for extended periods of time.
It’s a good idea to use a timer to ensure you don’t forget and accidentally leave lights on over night which may lead to stressed and unhappy fish!
What Types of Light Are Available For Fish Tanks & Which Should I Choose?
Having some kind of artificial fish tank light is extremely common and – so long as you’re responsible and follow the recommendation to ensure lights are always turned off overnight – there’s no reason not to enjoy one in your own tank, especially if you also have live aquarium plants.
The most popular types of lighting available for a freshwater tank include:
Fluorescent Lights
These are super common and come in a single unit with four to six tubes. You can choose different colors of tubes according to your preference, but red, white light, and blue lighting tend to be the most popular choices.
Light Emitting Diode (LED) Lights
LED lighting has gained in popularity in recent years. They’re inexpensive to run, last far longer than fluorescent tubes, and create a mesmerising shimmer effect.
Some people believe LED light can cause excessive algae growth, but the reality is that too much of any light source can be an issue.
Metal Halides
This high intensity lighting has low running costs but can be pricey to maintain due to the high cost of bulbs. However metal halide lights do provide the same ethereal shimmer effect as LEDs.
Incandescent Bulbs
These tend to be less commonly used since they can give off too much heat.
With the above in mind, my preference is LED.
Which Color LED Lights Should I Choose For My Fish Tank?
There’s a wide variety of LED lighting available in different color spectrums and combinations, including:
- Yellow
- White
- Blue spectrum
- Red spectrum
- Green
The visible light spectrum is made up of seven colours, and appear white when all colors are present.
Let’s take a closer look at each…
White Spectrum Light / Yellow LED Lights
The visible light spectrum is made up of seven colours, and appear white when all colors are present.
The reality is that specific colors are unlikely to be all that important for your tank, with aesthetic playing a leading role in choice. With this in mind, white bulbs are often a popular choice since this color looks closest to that of natural daylight hours.
Blue LED Light For Fish Tank
Blue aquarium light is very popular for it’s calming ambience, which is said to mimic moonlight and serve as a good transition from daylight to night time.
Blue light is also important if you have live aquatic plants tank, since it provides the energy for photosynthesis.
Keeping fish can benefit your wellbeing.
Green LED Light
Green light tends to be less popular with fish keepers, however fish themselves are drawn to this color! It’s a popular choice with anglers since it tends to attract most fish compared with other colors.
Red Light LEDs
Red color light can be a good choice for a planted tank, helping to deepen red pigmentation in live plants.
Benefits of Owning An Aquarium
Did you know that keeping fish can benefit your wellbeing?
It’s well-documented that interacting with animals and stroking them in particular can reduce stress and improve mental health. Research carried out by Plymouth and Exeter universities also provides robust evidence that keeping fish can alleviate stress and anxiety, and improve wellbeing.
Those aquariums you see in your GP surgery or dentist waiting room are not just for decoration – in studies assessing people’s physical and mental responses to watching fish, there were noticeable reductions in blood pressure and heart rate, and positive impact on overall wellbeing.
Steps For Setting Up a Tropical Fish Tank
1. Fit Light, Filter, and Heater to Aquarium
These items are essential for creating the right environment for your tropical freshwater fish to thrive. Check with the manufacturer of your filter whether or not it should be fully submerged.
2. Purchase and Clean Decorations to Fill the Tank
Doing this now means you’re able to position items where you want them placed easily, without getting wet!
3. Fill the Tank With Water
Fill the tank with tap water. It’s recommended to first wash and add the gravel you’ll be using, otherwise you’ll find the water goes very cloudy, and it may take several hours to settle.
Tip: Place a dinner plate on top of the stones when filling, to help prevent residual gravel dust being kicked up into the water.
4. Switch on Filter and Heater
Depending on the size of your aquarium, the heater will probably take a few hours to bring the temperature of the fish tank up to 24ºC.
5. Treat the Water
Tap water is suitable for humans to drink because of the minerals etc we add to it, however those minerals make it toxic for an aquarium. There are products available which can neutralise these, removing chlorine, chloramines, and heavy metals, making it safe for fish more quickly.
Once you’ve treated the water, perform a test to check water pH, nitrate levels and so on. Using test strips provides reassurance that your aquarium is now safe to add fish!
6. Research Fish
I skipped this step as we were al too excited and were confident we’d get good advice from our local aquatics store. Unfortunately, while the advice was good, the gaps in my knowledge were large and I was not made aware of everything I needed to know to make the best informed choices!
Tip: It’s important to consider how aggressive the fish you wish to purchase are, as they may limit what else you can keep in your community tank. Also be mindful of how many fish should be kept together, both in terms of individual species and the aquarium as a whole.
7. Buy Your New Pets!
I was recommended danios as a first fish since they’re relatively hardy, so are most likely to survive early introduction to a new tank. However, I’ve since discovered that they can also be semi-aggressive and may nip at some other/smaller species.
Had I known this prior to making a purchase, I may have made a different choice – I will do my own research in future!
Tip: Don’t forget you can always start off with just a few cheap fish and add to the community later.
Setting Up a Tropical Fish Tank FAQ
1. How Much Light Do Fish Need?
Fish should have around 8 – 12 hours of light. If your fish tank also has a blue light, this can be used in the evening to mimic moonlight.
All artificial light should be switched off overnight to provide fish with sufficient hours of darkness to support their natural circadian rhythm and prevent them from becoming stressed.
2. Can Artificial Lighting Contribute to Overgrowth of Algae?
Some people believe it does, and others say not. Research shows that algae grows faster in some colours of light than others, which suggests that too much light can definitely contribute to the issue.
This is one more reason to ensure lights are switched off more than they’re on!
3. What Fish Can You Keep in a Tropical Freshwater Fish Tank?
Some of the most popular fish to keep in a small-ish aquarium include tetras, guppies, and mollies. You may also like to consider a bottom feeder such as a loach, catfish, or goby.
4. What Else Can You Keep?
Shrimp!
I really wanted something different in our tank. At the time of writing we currently have three Amano shrimp. We relocated our danios to another tank and introduced six of these little guys!
5. How Often Do You Have to Clean a Tropical Freshwater Aquarium?
It’s recommended to do a partial water exchange every couple of weeks. This involves draining around 25% of the tank before refilling with fresh water of a similar temperature.
6. What Temperature Should a Tropical Fish Tank Be?
A tropical fish tank should be between 24 – 27ºC, and heaters are designed containing a thermostat to adapt automatically to ensure the desirable water temperature is maintained.
7. How Long Do You Have to Wait to Put Fish in a New Tank?
Some experts will suggest waiting a week to two weeks after setting up your fish tank, in order to allow a suitable biome to form. However, some products can be used together to treat a new aquarium, enabling you to purchase fish the same day.
I decided to be brave and test the theory with a few cheap fish despite being advised against it by the local aquatics centre – and they’ve been totally fine! Phew.
You may prefer to start off with some more hardy fish to err on the side of caution, but if your kids are desperate as ours were, there’s no reason not to go for it if you’re using the right products.