What is T5HO Lighting?
T5HO lighting is a fluorescent tube lighting system specifically designed for aquariums. The 'T' refers to Tubular and the '5′ is the diameter of the tubing in 1/8 inch increments. In other words, the tubes are 5/8 inch (or 13mm if you prefer metric).
As the diameter of the T5HO bulbs is very thin, this format has many advantages for aquarists, so it is not surprising that it is by far the most popular being used in aquarium lighting. More lights can be fitted into your hood space and pump out more lumens without having to use more powerful lamps. As a general rule you should use one T5 light for ever three inches of tank, going from front to back.
T5 High Output Explained
HO refers to High Output. These HO systems are not interchangeable with NO (Normal Output. NO systems are found in some entry level hoods you might find in a local pet store. Serious aquarists use HO or even higher output lamps, so when reading aquarium lighting information, it's most likely than T5 is used to mean T5HO.
There are no T5 VHO (Very High Output) systems being produced, however VHO can be achieved by overdriving your T5HO system using Ice Cap ballasts. This will get you a strong lighting system - but at the cost of reduced bulb life, the lights will also generate significant radiant heat; enough to affect your tank temperature.
Why T5HO is Popular for Aquariums
T5HO bulbs all use the modern electronic ballast. These ballast offer numerous advantages over the old magnetic ballast: lower noise - almost silent running, lower energy consumption, lower electricity bills, and prolonged bulb life. A good thing for the environment. Be sure to recycle your old bulbs when its time to replace them.
Another advantage of T5HO lighting systems is they run cool enough that they won't heat the water too much. You can mount them very close to the water -achieving efficient lighting for your dollar. To do this you will need to have a glass or perspex splash shield to protect the lighting from splash damage, and corrosion for saltwater tanks. Use waterproof end caps to keep the sensitive contacts protected from moisture.
T5HO lighting can be installed as a convenient fully assembled fixture, or you can retrofit the T5HO lights to your existing canopy or hood.
T5Ho lighting systems are happily enjoyed in all kinds of tanks. Whether you just want to keep a fish only tank, or you have planted aquariums, or you're a reef keeper -T5HO can meet the majority of aquarium lighting needs.
T5HO For Planted Tanks
Planted tanks will need a plant growth lamp giving red AND blue light. Plenty of red light will encourage growth, growing your tanks tall. The blue light will add vigor to the plants body, getting them thicker and bushy. The good news is that T5HO bulbs come in a variety of colours from warm red through daylight white all the way to actinic blue. 6500K is a good starting point for freshwater planted aquariums.
T5HO For Fish Only Tanks
Fish only tanks can use white spectrum lamps around 5000K to 8000K. The fish will be fine anywhere in this range. The choice comes down to your preferences for your viewing pleasure - which color temperature lamps bring out the best in your fish.
T5HO For Reef Tanks
Mini reef owners, and soft coral reef keepers can also stick with T5HO lighting. For your reefs you will need actinic lamps giving 10000K to 15000K. It's a credit to T5HO system that the lights are capable of providing a healthy environment for reef tanks. As mentioned earlier, T5HO meets the majority of aquarium's light needs - but there are exceptions.
The exceptions being the SPS corals and invertebrates such as clams and anemones. These blue light hungry critters will not be satisfied with T5HO alone and you may supplement the blue spectrum light with a Metal Halide lamp. The same thing goes if you have a deep tank, over 24″ in depth. T5HO won't get light all the way to the bottom, so juice your system up with a MH bulb.
T5HO: Cooling Not Required But Highly Beneficial
Cooling isn't needed for the health of your tank, but is necessary for the health of your bulbs. Target your cooling fan on the T5HO tube's cool spot - usually it's the label end. This will let the bulb run at its optimum efficiency and keep it producing the required light spectrum for a longer period.
T5HO bulbs will not last as long as NO ones. The exact lifetime must be calculated based on your tank's setup; the cooling system you have installed and the photoperiod you use for your day lighting.
Cheap T5HO Lighting - A Warning
Always choose brand name items from well known companies. As the hobby explodes in popularity, this has brought a host of cheap imports. Now, these imports do help us by driving down the price of quality goods, but you will not save money by buying from unknown manufacturers. The amount of returns and refunds and customer dissatisfaction means that most decent pet stores quickly learned to stick to the quality brands, you do see these kind of cheap products on otherwise decent sites like Amazon -along with many customer tales of aquarium lighting misery.
Maximize Performance and Efficiency of T5HO
Reflectors are one of the best ways to maximize T5HO performance. Cheap to buy, easy to install. They reduce your electricity bill and get the most out of your T5HO lights. Reflectors will effectively last forever if you wipe them every so often (especially if you get saltwater evaporation residue).
I can't imagine anyone manually switching their T5HO aquarium lights every day when an automatic timer takes care of the task like clockwork. What's even better is you can switch to lunar lights at night -it's cheap to get these lights and then you have a beautiful and intriguing nocturnal display.