How to Buy Lighting for Your Aquarium

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How to Buy Lighting for Your Aquarium


Aquarium lighting fulfils two functions; it enhances the appearance of the set-up as well as supplying vital light energy to plants, aquatic organisms and the fish themselves. If, for example, your aquarium contains hard and soft coral, these varieties will not survive without the appropriate lighting conditions. Lighting also has an influence on fish behaviour and is important for the overall health and sustainability of the aquarium.

Lighting is a matter of personal taste and aquarium lighting on eBay  is no different. However, there are some material factors to take into account before you buy furniture like this. These are principally the size & depth of the aquarium and the type and variety of vegetation you plan to introduce into the tank. Plants do need light to thrive and some aquatic plants need more light than others.

Fish can survive without light, but a dark tank is hardly a good decorative feature. If you have fish, but no plants in the tank, too much lighting will encourage algae to grow. You therefore need to limit the amount of hours per day your tank lights are left on (see paragraph below). It’s worth stressing at the outset that you must only ever use lights specifically designed for aquaria – any other kind of lighting simply won’t work. The right lighting can make the difference between an aquarium that succeeds and one that fails.

Types of Lighting

There are three basic types of light:

  • Standard fluorescent
  • Compact fluorescent
  • High intensity metal halide

These are each designed for a different set of conditions within the aquarium.. LED lights are also available but their high price has so far restricted their popularity amongst hobbyists.

Standard Fluorescent Lights

This are the most affordable type of aquarium light and is commonly included if you’re buying a new starter tank, starter tanks. Their output typically ranges from 15 to 40 watts with Kelvin ratings of between 3,000° and 10,000°. Kelvin is the name of the measurement scale used for colour temperature.

Standard fluorescent lights are best suited to fish-only aquaria,, whether fresh or saltwater, and offer a variety of colour choices including:

  • white
  • blue
  • the warmer colours
  • full-spectrum, which creates a daylight effect

Within this range there are specific bulbs to help re-create deep marine conditions, supplying the appropriate energy for photosynthetic coral growth. Within the category, you can also buy bulbs which stimulate plant growth and work particularly well in aquaria which have been stocked with dense vegetation. Running costs and replacement costs for these bulbs are not expensive.          

Compact Fluorescent Lights

Compact fluorescent lights produce significantly higher output than a standard fluorescent light and usually incorporate either two or four bulbs. These compact, space-saving units provide high light intensity from a convenient single source without compromising any of the benefits of fluorescent lighting:

  • Wide bulb selection
  • Reduced heat emission
  • Economic operating costs.   

Their output typically ranges from 10 to 100 watts with Kelvin ratings of between 5,000° and 10,000°. However, the more intense light generated by these bulbs does produce more heat and for this reason they may need to be installed with special hoods and fans.


It’s possible to buy reflectors for fluorescent lighting systems. These are long metal strips which fit above the light bulbs, reflecting light back down into the aquarium.. They should improve the lighting ambience in the tank. If you think that your fluorescent bulbs are not emitting enough light for your plants, it would be worth testing reflectors before you spend more money on a lighting upgrade.

Metal Halide Lights

These lights produce a high intensity discharge (HID) and would tend to be used by the more advanced aquarium enthusiast.  Metal halide lights are very effective in promoting vegetative growth and are particularly suited to reef aquaria. They can also be recommended for any aquarium deeper than 24 inches where other lighting systems would probably fail to penetrate.    

Their output typically ranges from 175 to 1000 watts with Kelvin ratings of between 5,000° and 20,000°. In terms of luminosity, Metal Halide lights have similar characteristics to the sun but they’re very expensive to buy as are running and replacement costs. Like compact fluorescent lights, they will normally need to be installed with a cooler fan.

Metal halide lights are quite a bit more difficult to fit than other types in that they are suspended above the tank. The effect of this is to create a gap between the lights and the tank, meaning that light can escape and reflect off other domestic objects such as TVs and mirrors. If your TV set is in the same area as the aquarium, bear in mind that metal halide aquarium lighting can become quite distracting.

Light-emitting Diodes or LEDs

It’s possible that LEDs may eventually gain popularity but there needs to be a big price reduction before this happens. Price apart, they do offer many advantages over the types of lighting described above. Benefits include -

  • lower energy consumption
  • a cool running temperature
  • more durable, because there is no filament to break
  • more flexible to position because of their compact size
  • a much longer life span


You will need to install fluorescent lights in correctly sized ballasts, which transform energy from the power outlet to the bulbs. Each bulb size has a specific type of ballast. If you're buying new, most set-ups will include a tank with both lighting and a ballast system.

How Many Lights Should You Buy?

The consensus tends to be that:

  • One standard fluorescent unit is probably enough for a 20 gallon aquarium.
  • You should add an extra light for a tank capacity of between 20 and 55 gallons
  • You should add one more light for each additional 20 gallons thereafter.

 These are just basic guidelines which you will need to supplement for any special functions or effects.

When Will the Lights Need Replacing?

Over time, aquarium lights will lose their intensity and will need replacing so that they continue to provide essential light energy to plants and organisms. From experience, it‘s advisable to change bulbs every eight months or so. The replacement price will depend on the size of light required, but as a guide, fluorescent bulbs for a four foot tank would normally be found at an affordable price range.

How Long Should Aquarium Lights Stay On?

Lighting patterns should follow those observed in tropical climates, which is where most of the fish, plants and organisms hail from.

  • Aim for up to ten hours of illumination per day.
  • You should use a timer to control this.

Logging on to eBay

Now you've worked out which type of aquarium & you want to buy, find it quickly on eBay.. While you shop for your aquarium, you might also want to look up other aquarium related merchandise such as filtration units, heaters, lighting, stands and hoods.

  • Go to
  • Click ‘Pet Supplies’ from the main menu 
  • Click  ‘Aquariums & Bowls’ (this section includes essential accessories)

At any point you can use keyword search (top right hand panel) if you prefer. Once you get to the appropriate section of the website, you then need to decide exactly what and how you want to buy.

  • Do you have a particular brand in mind?
  • Are you buying new or used?
  • Alternatively, do you want to set a price?
  • Do you want to buy now?
  • Alternatively, do you want to enter a time-limited bidding process?

All these questions take the form of clickable boxes on the website, and it’s a simple matter to progress the purchase from this point, particularly if you’ve prepared the answers in advance.  

Buy Now or Auction Format

If you’re a newcomer to eBay,, you may feel safer with the ‘buy now’ format.

When you become more practised, the auction format is potentially more rewarding, particularly if you happen to be buying in larger volumes,

Product Presentation

The way products are presented on the website will give you an indication of the seller’s professionalism. Uncluttered pictures are the best way of demonstrating product detail and quality. Also look for honesty, particularly in the description of used goods. Information should include brand, age and condition. The disclosure of imperfections will prevent any future misunderstandings. Reasons for the sale can also be quite informative and sometimes reassuring.

Seller’s Trading Record

You will find ‘top rated sellers’ (regular eBay sellers who have established an excellent trading record) indicated against some sale items and they obviously represent the highest possible level of security for buyers.

Payment Information

Make sure you understand the total price of the item, and the payment options.

Check that postage costs are included and search for any possible conditions of return. An online payment system such as PayPal effectively gives two-way protection and means that payment can be made without any hassle.

Next Steps

If you can't find exactly what you want, try browsing eBay Stores or tell the eBay Community what you’re looking for by creating a post on Want It Now, or save a search on My eBay and eBay will email you when a matching item becomes available.

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