-
Step 1
There are two main options to consider when purchasing metal halide bulbs. Single ended (SE) or double ended (DE). Both come in varying watts and both have it's advantages and disadvantages. One halide bulb on average will cover a 2' x 2' space. Most 4' tanks require two halide bulbs.
-
Step 2
SE bulbs are mogul based which means they screw into a light fixture like a normal light bulb would. They are larger then DE bulbs and require more space to mount. They typically put out a wider spread light radius then DE bulbs, but this is not always the case.
-
Step 3
DE bulbs connect on both ends and are much smaller then SE bulbs. The biggest advantage with DE bulbs is the ability to mount them in smaller light fixtures and spaces. They emit a very bright light for their size and are quickly becoming very popular.
-
Step 4
The next thing to consider is the wattage amount. SE bulbs typically come in either 150w, 175w, 250w, or 400w. DE bulbs typically come in 70w, 150w, 250w, or 400w. Choose the proper watts for your size aquarium and the coral species you wish to keep. Typically 150w is good for tanks under 18 inches in height. Tanks that are between 18 inches and 24 inches do well with 250w bulbs, and anything over 24 inches typically use 400w bulbs.
-
Step 5
The next choice to consider is the Kelvin rating, or k spectrum. The most popular choices are 10k, 14k, or 20k. The lower the K rating, the less blue and more yellow the bulb will have. 10k emits a yellow or natural sun look. 14k bulbs are a nice mixture of a bright white with a blue tint to them. 20k bulbs are usually very blue or purple in color.
-
Step 6
Metal halides are a great choice in saltwater aquarium lighting. IMO they are the best option and offer many different color ranges to enhance the colors of your corals and fish.
