Cookies seem to be disabled in your browser, therefore this website will NOT work properly! Please, consider enabling Cookies in order to maximise your user experience while browsing.
Recent discussions at Aqua-Fish+
  1. PondSealer at Maintainging a garden fish pond tasks on
  2. TheFishWorks at A guide on growing aquarium plants with FAQ, forum and species on …display more of the recent discussions
  3. Salviashaman at A guide on caring for Congo tetra (Phenacogrammus interruptus) on
  4. Salviashaman at A guide on setting a South American blackwater stream biotope aquarium on
  5. Figureguy at Chemistry of Aquarium Water with FAQ on
  6. Jackson20 at A guide on feeding aquarium fish frozen foods on
  7. Senator Wisdom at Bloodfin tetra (Aphyocharax alburnus) on
  8. CayceR at A page and forum devoted to keeping Blood parrot cichlids on
  9. Ness at A guide on raising African Dwarf Frogs with pictures and forum on
  10. Terry Mitchell at A guide on breeding, feeding and caring for L333 Pleco on

Aquarium lighting FAQ and tips

a guide to lights for freshwater aquariums

Aquarium lighting, resized image

Brief Description

This page is devoted to fish tank lighting, answers FAQ, and offers forum for asking and sharing ideas. If you came here looking for online suppliers of aquarium lighting, simply click this link! Bear in mind you're welcome to submit story of your aquarium at the bottom of this page! Simply scroll down and you'll find answers on your questions!

Before you decide to buy an aquarium lighting system there are a few facts you should know. Always focus on more aspects than only price, given discount or cheap offers. It's necessary to understand the purpose of a lighting system in a fish tank, and only then one should go ahead and buy. This guide is here to help you and it has been written by experienced fish keepers for everyone who needs advice regarding aquarium light.

Imagine, you are a colourful tropical fish. You swim in warm water, with lot of plants, in which you can hide and of course you know where you are swimming to. Do you know how this paradise may exist? It is because of the sun. Sunshine is a perfect light. Thanks to the sun the life exists on the Earth's surface. Thanks to the sun I can write this article now. As you all know, it is because of the photosynthesis. So you see, that the light is very important. And an aquarium needs it too. That is the reason why you have to buy a specialized aquarium lighting.

When you are buying an aquarium lighting, you have to choose it carefully. The right type of the lighting is very important for the aquarium. It is because plants depend on it. If you choose a wrong type of the light, it may cause that your plants will not grow, but algae will. But it is important in the fish-only aquariums too. It is because fish need to see where they are swimming to and what they are eating. Fish should have from 10 to 12 hours of light trough a day. If you shut down the light suddenly, fish may be scared. The best way how to shut down the light in the aquarium is to shut it down few minuter before you shut down the light in the room. And before you turn on the light in the aquarium, turn on the light in the room, if you have a darker room. Some aquarists have a night light in the aquarium. It is called lunar light too. In the nature, such light is normal for fish because at night it is not as dark as in a room.

There are two things that are important when you are choosing an aquarium lighting system: colour spectrum and brightness of the light. Manufacturers makes lights in some colour spectrum variants. The best colour for plants are red and blue parts of the spectrum. But if you have a fish-only aquarium, you can choose a yellow-green part of the spectrum, but the best is a full spectrum light. The aquarium will look more heater. The brightness of the light is more difficult to choose. It is because you have to know how much light plants will need and how big will your aquarium be. You need to know exactly how deep and wide will your aquarium be. It all affects the brightness in the tank. The more deeper your aquarium is, the more stronger light you need. Generally, a tank should have got from 0,0015 to 0,0022 W on a square centimetre.

The best way how to measure how much light you have in your aquarium, is with luxmeter. The intensity of light is measured in luxes. Freshwater aqarium plants need maximum 5 000 lux and saltwater plants, sea-flowers and corals need more than 6 000 lux. It is very important to know how much light need your plants, because if they have more light than they need, they will not be as pretty as they can be and algae will grow in your tank. So here are some examples of how much light need some species of plants: Cryptocorinae and Vesicularia need maximum 500 lux. They like mild light. Anubias, Echinodorus, Sagittaria and Hygrophila need 500 – 1 000 lux. It is a gentle light. Bacopa, Ceratopteris, Egeria and Ludwigia like quite shine light 1 000 – 1 500 lux. Vallisneria, Cabomba, Myriophyllum need the most light – over 1 500 lux.

The most common aquarium lightings are Fluorescents tubes. This type of aquarium lighting can be made in many colour spectrum and many sizes and they last for about one year. They also can simulate daylight. Tungsten and Halogen Lamps are used in some cases, but they are not a good choice. They are maybe cheaper, but they need more energy and lasts for a short time. They also heat up the aquarium and they have not the right colour spectrum for growing plants. This is also the the cause why normal lamps can’t be used. By the way, unlike like lamps specially made for aquariums, ordinary house lamps would not light up the whole aquarium the same way. Compact Fluorescents are like fluorescent tubes, but they last longer. They also need less energy even if they make more light. This can be possible because it looks like one long fluorescent tube shaped to U. Most lightings need more space, but this doesn´t.

Never try to save a few dollars if you're going to lose quality. Sometimes a small saving can lead to dramatic change in terms of light quality. Inexpensive items may lack in quality sometimes, however it isn't the rule. As it has been mentioned above, when buying aquarium lighting always ask for information about spectrum/intensity. Bear in mind that light alone isn't sufficient to grow plants in general; One needs quality fertilizer and substrate as well. Fish excrements don't contain all nutriments that are needed for plants growth.

Links to other related articles at

Aquarium lighting

Aquarium lamps

Aquarium neon lighting

Aquarium lighting detail

Images sources:,

Additional picture

We are not advertising any product. Images are informational only!

Aquarium lighting

Feel free to visit Aquarium Lighting at too!

Additional information about aquarium lighting

We've added new answers on March 18th 2011 due to merging with articles. All of the below-listed questions have been asked by visitors of Aqua-Fish.Net. In some cases the questions may be partially answered in the article above, however listing them one by one makes the answers easier to find. You're welcome to submit own questions, just ensure that they haven't been answered already, please

  • Is the t8 or t5 aquarium light better?

    Answer: T5 bulbs are better to use because their smaller diameter allows more bulbs to be fit into the space of the aquarium hood. This creates more lighting allowing for better, deeper illumination.

  • What light color is best for aquarium?

    Answer: When dealing with a freshwater aquarium the lighting color is not as important compared to what is needed for a saltwater aquarium. When dealing with a saltwater tank aquarists usually prefer blue lighting because it penetrates deeper into the water where corals are more responsive to it. For freshwater aquariums it is more beneficial to have broad spectrum lighting.

  • What type of light should I use for my aquarium?

    Answer: The best lighting for an aquarium would be a light fixture that can hold as many broad spectrum light bulbs as possible in the space of the aquarium hood. Using a timer that creates natural daylight hours and natural dark night hours will allow the fish to get used to a healthy time schedule. Moon lamps are also available for the sake of night viewing. Some nocturnal fish are best observed at night while the lights are out.

  • When do you turn the light on for fish tanks?

    Answer: In the morning if possible; Lighting for fish tanks is normally run for 10 hours per day on planted tanks, unplanted tanks the lighting is purely for viewing the fish so the hours are by the keepers choice.

  • What is a t5 light?

    Answer: A t5 light is just another type of fluorescent lighting, the name t5 is referring to the size, a t8 light bulb will be about 1 inch in diameter, where was the t5 is about 5/8's of an inch in diameter, also there is a slight difference in length between a t5 and t8 bulb (a t5 is shorter). One final difference between a t5 and a t8 are the pins on each end are much closer together on a t5 bulb.

  • What kind of aquarium lighting would you use for fresh water plants?

    Answer: Just about any bulb that is rated to have a color temperature of 6500K will satisfy your average aquarium plant. Some plants may require specialized bulbs or lighting conditions such as filtered light. To achieve filtered light, one may choose to put a screen filter between the light and plant or simply plant it under another plants large surface foliage (water lilies, water lettuce etc). Other plants require a larger spectrum and can be satisfied with Hagen flora glo bulbs. Other plants require a color temperature of 6500K/10000K/12000K in addition to some parts of the UV spectrum. All of these temperatures are available, however some require you to purchase Metal Halide, mercury, or power compact fixtures and bulbs.

  • Which lighting should I use for a planted tank?

    Answer: The correct amount of wattage for a planted tank is normally 2 watts per gallon of water. The kelvin rating of the tube is also important as the correct light spectrum is required. Tubes between 5000-7000K are fine.

  • When should I switch off the lights in aquarium?

    Answer: In the evening or night if possible; When you decide to turn the lights on and off is entirely up to you. If the tank contains live plants, the tank should have at least 10 hours lighting per day.

  • Why do aquariums need lighting?

    Answer: There are 2 main reasons for lighting. The first being; that it allows the fish keeper to view their aquariums. The second reason is that plants need light to grow by photosynthesis, in a reef tank the corals use light to grow.

  • Why do my fish change color when the aquarium lights are on?

    Answer: All lighting uses different parts of the color spectrum depending on the Kelvin rating of the lights. Because the lighting is artificial it will give the impression of different coloration on the fish. Buying the correct lighting for showing up the reds and blues on the fish will help.

  • What color of aquarium light should I use?

    Answer: Choosing the most natural aquarium lighting possible is very important. Providing day light and night light is extremely important for the comfort of the fish. Use fluorescent lights during the day and lunar bulbs at night with a timer for consistency.

  • Where can I buy aquarium lighting?

    Answer: Local pet shops stock a wide variety of aquarium lighting. If you need to fulfill a specific need, online shopping centers such as, or will satisfy your needs. If you are a qualified electrician, there are many different DIY plans available online. It is important to always follow manufacturers guidelines and GFI protect any device used in or around water.

Online suppliers

If any of the links within the below-shown list doesn't work, tell us about it through the form that is available at the bottom of this page, please!

Please, verify whether your login and password are valid. If you don't have an account here, register one free of charge, please. Click here to close this box.

You have been logged out successfully! This box will close automatically!

Something went wrong during processing your message, please try again!

Your message has been sent, thanks a lot!

Page has been saved, refresh it now, please!

The page has been created, you will now be redirected!

URL already exists!

Path to the photo is not unique!

Really delete this page from the database?

The page has been removed successfully, you will be redirected now!

The page couldn't be deleted!!

Unfortunately this page doesn't allow discussion. Please, find any other page that fits your area of interest as over 99% of our pages allow discussion. The reason why no discussion is allowed here is this page is too general. Thanks a lot for understanding! Click here to search, please!

Really delete this comment from the site?

Really delete this image from the site?

Really delete this image from the site?

Selected comment has been removed successfully!

Selected image has been removed successfully!

Either login or email address is required

Account has been recovered, please check your email for further instructions