Basics for Fish Tank or Aquarium Lighting:
Just placing a tank in direct sunlight can cause overheating, accelerated algae growth, and a host of problems. Artificial light for an aquarium therefore is a necessity.The goal of aquarium lighting is to recreate the natural habitat. Incorrectly lighting a tank can put undue stress on fish and aquatic organisms causing poor health and interrupting natural cycles of behavior, it may also promoting algae growth. About 12 hours of night light is also needed to promote good health and natural behaviors like spawning.
- The preferred light color for aquarium is either 10000-12500K white light, or a mix of 6000K white and blue light in a ratio of 1:1.
- The preferred lighting length is 6-12 hours for a fish only tank and 10-12 hours for a tank with plants or a reef.
- The typical power ratio LED/fluorescent/HID=1/1.4/2.4
- The life time of an LED is 500,000 hours. Blue LEDs are significantly better than blue fluorescents – which will degrade in half a year.
Color temperature gives you an idea of how things in your tank will look.
· Blue-colored light will enhance blues in fish and aid in photosynthesis for plants.
· Green-colored light will make the tank look brighter to human observation because human eyes are sensitive to green light.
· Red-colored light will enhance the reds in fish, aid in photosynthesis for plants, and enhance the reds in any red plants.
Wavelength is used to determine useful light for growing plants (both blue light and red light are needed for photosynthesis).
For green plants the light absorption peaks that are most important are as follows:
1. Chlorophyll-a: 430nm/662nm
2. Chlorophyll-b: 453nm/642nm
3. Carotenoids: 449nm/475nm
Blue Wavelengths vs. Red Wavelengths
· Blue light: optimizes plant leaf development and penetrates water better and more quickly than red light
· Red light: optimizes stem elongation and plant color and is more efficient than blue light
· Plants are able to start photosynthesis once there is sufficient light.
Plants and Wavelengths
· Red pigmented plants use more light in the blue area of the spectrum.
· Green plants appear green because they are reflecting green light not absorbing it.
· Green algae uses the same light as plants.
· Blue-green algae (cyanobacteria), which contains Phycocyanin, absorbs light in the low 600nm wavelengths.
Lighting cycle is used to simulate day/night cycles.
Cycles in Hours:
· 6-12 hours for fish only tank
· 10-12 hours for plants and reef tank
· 12+ hours per day will cause algae blooms
· Algae need a long and uninterrupted lighting period to function properly.
Cycles of Intensity:
· Creating an hour of dawn/dusk lighting period at the start and end of the lighting period to simulate natural lighting is suggested.
· Creating a 12 hour of low-intensity night lighting period to simulate natural lighting is suggested.
· Creating a ‘siesta’ period in the middle of the intense lighting period is good for plants, but may affect fish.
Lighting Intensity, Wavelength, and Color Temperature Standard Set-ups:
Fish-only Tanks:
· 1-2 W Sunlite LED per gallon.
· 5000K to 6000K is recommended – more red light will highlight fish colors
· Fish tanks with live rock, for the purpose of beneficial bacteria or appearance, do not need high output lighting
Plant Tanks:
· Need to balance the red light and blue light, (2:1 red light to blue light). Some green light is suggested for better viewing appearance.
- Strong red light can cause aquatic plants to grow tall and thin and will tend to promote blue-green algae growth
- Strong blue light can cause plants to grow compact and bushy and will tend to promote green algae growth
· Some plants are able to change the pigment they use for photosynthesis depending on available lighting, for example:
- Red-leafed plants turn green if the lighting is too low, not enough blue and/or green light.
- Green-leafed plants produce red foliage when closer to the light source or with overly bright lighting.
Reef Tanks:
· 2-4 watts of Sunlite LED light per gallon
· Preferred color temperature: ~10,000K
· Reef tanks need more lighting than fish only tanks, because they typically contain soft and hard corals that harbor zooxanthellae (symbiotic algae), which must thrive in order for the coral to live.
· Hard corals need more light than soft corals
· Deeper tanks need even more light, because light intensity on an object decreases in proportion to the square of the distance between the object and the light source
· Newly acquired corals should be placed on the bottom of the tank and gradually moved up, or should gradually over 1-2 months be exposed to the full light
· When lights are replaced or added, a reduction in the initial intensity should be considered.
24″/21W Sunstrip40 Fish Tank Light
· Water proof, not for use under water
· 21W/2900 lumens, replaced 1 30W fluorescent lamp
· Directional, 120 degree (standard), or 90 degree (recessed) in all directions
· Available in white 5500K, 10000K, 12500K and blue
· Thin profile aluminum bar – 24″(L) x 1.6″(W) x 0.4″(H)
12″/15W Sunstrip40 Fish Tank Light
· Water proof, not for use under water
· 15W/1900 lumens,
· Directional, 120 degree (standard), or 90 degree (recessed) in all directions
· Available in white 5500K, 10000K, 12500K and blue
· Thin profile aluminum bar – 12″(L) x 1.6″(W) x 0.4″(H)
20″ Sunstrip10 Fish Tank Light
· Water proof, not for use under water
· 7.5W/900 lumens, Replaces 1 15-watt fluorescent lamp
· Directional, 150 degree in all directions
· Available in white 6000K, 10000K, 12500K and blue
· Thin profile aluminum bar – 0.20″(L) x 0.4″(W) x0.31″(H)
Problems with Current Lighting Methods
Problems with Metal Halides:
1. Less efficient
2. Can get very hot and need small fan to circulate air flow across the lamps (sometimes even a chiller)
3. Many metal halides require a 100-200 hour burn-in period until their true color comes out
Therefore, the color of a new bulb may be significantly different than the color of the bulb it replaced, and should be kept in mind when bulbs are replaced
Problems with Fluorescent Blue:
1. Color spectrum of the tube changes as it ages and will cause outbreak of algae growth
2. Produces less light over time
3. Linear fluorescent tubes should be changed out every six months and compact fluorescents every year