Aquarium lighting for the novice can be confusing. Aquarium lighting is very important though, and it is important you purchase the right type of light fixture for your aquarium for both the best health and the best pleasure your aquarium can provide you with.

Aquarium lighting for saltwater fish, the main purpose of your lighting is to provide the correct spectrum and wattage to assure your animals look their best and stay nutrionally healthy through what their body absorbs. The correct lighting on a fish only tank will affect the reproduction cycle of your tanks contents and will also affect the types and ability for nescessary beneficial algaes to be produced.

If you have a reef aquarium, the lighting is even more important because the majority of corals and invertebrates use a process called photosynthesis to feed themselves and keep nutrionally healthy. Without the intense lighting from either power compacts, VHO's or metal halides, a coral or inverts metabolism will slow down and often times results in a slow death. A general rule of thumb is to have 3 - 5 watts per gallon for a reef tank. Higher wattage is nescessary for some advanced corals and invertebrates.

Power compact lighting is very good for reef tanks because they are VHO (very high output) bulbs compacted in a small space. Easily installed, power compacts are so intense that watt for watt they will produce twice as many lux as a comparable VHO without any increase in heat! The power compact bulbs should be replaced about every 6 months to attain efficiency. After long periods of time the lights loose their intensity, and should be replaced. A ballast unit usually comes with these lights to handle the high power.

Soft corals are a perfect coral for power compact lighting. They don't require as much intense lighting and will do fine wonderful under power compact lighting.

Metal halides come in two varieties. HQI metal halides and Mogul mount metal halidess. they are easy to tell apart. HQI bulbs are double ended, and are quite small. Mogul mount metal halides have a screw in end like a normal light bulb. Either are very good lights to have for a reef tank because the lights are very intense and will reach deeper into the aquarium.

Heat though is a problem with metal halide lighting , they will get hot, so a fan is necessary to stop the tank from over heating. Often in warm climates a chiller may even be nescessary.

Aquarium bulbs need to be replaced about every 6 months. You should generally keep one bulb for every 3 feet of tank length and you should consider at least 4 watts or more of energy per gallon.

Planning to keep hard corals such as SPS corals, acroporas, milleporas? If so, you need to have the intense lighting metal halides provide for maximum color intensity and best health. . You should generally have 4-10 watts per gallon for these corals. So if you have a 90 gal. tank you would need 360 watts or more of energy for the tank.

To sum it all up, lighting is the most important item for reef aquariums. You can never have too much light. The more energy available from the lighting, the faster your corals will photosynthesiz and the healthier your tank will be.