Updated Apr 2021
When it comes to aquarium lighting, there are 3 key aspects to consider. Strength, Spectrum and Spread. A detailed guide on these factors is provided here. After that, a major decision is between using fluorescent T5 tubes or increasingly common LEDs. LEDs are sleek and energy saving, and generally work for most tanks-unless you are particular about unlocking vivid coloration in red plants.
LEDS THAT GROW AND DISPLAY RED PLANTS WELL
The select few that are able to unlock truly vibrant reds are listed below. The core difference between them and other aquarium LEDs on the market is that they primarily use RGB diodes and no white diodes. An example of the Maxlite Life Aqua Master Pro LED array is shown below:
This gives them a higher red/blue spectrum compared to most other aquarium LEDs.
This group of LEDs comprise of ADA Solar RGB and its copies.
Photo from Viktor Lantos, Green aqua showing ADA solar RGB
The Chihiros vivid is programmable and cheaper (but has fans) while the Life Aqua master pro is dimmable and water proof. The ADA solar RGB is a no frills unit but carries the ADA brand name. Due to exact diodes chosen for their RGB profile; there is also slight differences in visual coloration - the ADA solar RGB and UNS titan have a slightly deeper green tone compared to the Maxlite and Chihiros vivid.
OTHER LIGHTS WITH STRONG RED/BLUE SPECTRUMS
SBreef lights are another popular option among the technically minded crowd. The fixture is large and bulky, but comes with very high PAR values, considering the fixture cost. This fixture is for folks that favor cheap, high powered lighting, but are less concerned with the aesthetics of the fixture itself which is large and bulky. It is programmable with in-built electronic timer and its spectrum can be tweaked.
OTHER REASONABLY GOOD LED CHOICES
The Twinstar S series works well for smaller sized tanks. The S series has an attractive spectrum, and sleek build. We also like that they do not have fans which are another weak point in many light fixtures. The fixtures are slightly broader than thinner fixtures, but we find that this actually gives better spread in a tank. For 3ft (90x45x45cm) tanks and above, we would recommend having 2 fixtures. The other similar LEDs in this category is the Chihiros RGB.
Above: Twinstar S series by Twinstar Iberica
Among the many T5 fixtures on the market, we would recommend Hydrofarm's Agrobrite hydroponics range. Good reflectors, good build quality, fair price.
Sunblaster has good reflectors and provides fixtures that can be customised in terms of number (you can add individual light bars)- which is good for DIY enthusiasts.
Conversely, while not fancy, fluorescent T5 tubes are very stable and give very predictable results, as explained here.
For a T5 array, we recommend a mix of colours. A good neutral tone 4-tube combination would consist of 2 white/6500k bulbs matched with 2 pink bulbs. For stronger contrast, we would forego white bulbs entirely, and just use a mix of pink and blue/purple tubes. A white/orange tube can be used to balance out selections that are overly blue heavy. A 4-tube combination we like is 2X pink, 1X purple and 1X orange/warm white.
The Zoo Med Flora Sun featured below works well. We would also recommend the Giesemann Super Flora range, which has a reddish tint with spikes in the red / blue spectrum. Alternatively, Wavepoint bulbs work fine as well. The Dennerle Colour Plus bulbs are good as well.
Go for either the ATI series or Wavepoint (featured below) which has a number of choices.
Wavepoint (featured below) and ATI have a number of choices. However this is a bulb color that is not normally used unless you want a blue tint to the tank or are compensating for using many warm white/red tubes.
For warm whites, the Osram 2700K series featured here is established and works well. iPower has good options also. I like the Agromax and Dennerle's 3000k choices as well.
NEUTRAL 'DAYLIGHT' WHITES
Wavepoint has several choices (the Amazon picture featured below may look yellow but the specifications would be 6700K). The Giesemann Tropic bulb is good too. The key difference between using these bulbs (vis a vis everyday home-lighting daylight bulbs) is the better spectrum distribution in these horticultural bulbs. Many household bulbs have large spikes in the green spectrum (which human eyes are more sensitive to) while we would prefer spikes in red and blue for plant growth and which also give better colour rendition.