20141104 What Light for your Saltwater tank? Part 1.

One of the most commonly asked questions is the choice of lighting. What's appropriate for your critters? What's the best color temperature combination to bring out those colors? All lights seem so expensive, can I just DIY?
First, I must say that without proper training in light, physics, and electrical, everything I am going to discuss is entirely based on observation and real life experience.

LED light reflecting from the surface

Currently some there are many options for aquaria lighting. Among some of the less expensive but least light output are:
Regular T7 florescent tubes, incandescent bulbs, power compact lights
These lights are suitable for fish only aquaria or some of the non-photosynthetic or least light demanding soft corals. But in most cases will not provide enough energy for higher end corals and inverts to thrive
Some of the more sophisticated lightings are:
VHO T5 florescent tubes, Metal Halide bulbs, and LED lights
These lights tend to have a higher cost and drains more electricity, but can sustain some of the most light hungry creatures such as small polyp stony corals (SPS), large polyp stony corals (LPS), clams, anemones, etc.
Another option is DIY- if you are skilled in electrical, you can also design and put together your own lights. You can find many light parts, ballasts that are suitable for your project. Warning, if you do not construct the light correctly it can result in fire.
There are many other aspects of lights such as PAR, light's distance from the water surface, water depth, and light color temperature. We can save all them for the ensuing parts of this series.

In the mean time, there are some good readings I recommend from a couple reputable online livestock retailer:
Liveaquaria Light article
Pacific East Aquaculture Light article

Switching light

I felt the previous power compact lighting isn't delivering the kind of color I like in this tank, so I pulled out my old t-5 light 

Jumbo Duncan Coral

The Largest Duncan Coral I've ever seen is right here in my fish tank. Duncan coral (Duncanopsammia axifuga) has become very popular in the aquarium trade recently. Not only it is pretty to look at, it is also very easy to maintain, grows fast, and can be readily propagated with little to no effort. I have originally purchased my three head duncan from the local aquarium store, each polyp at the size of 1 inch across. That remained true for a short while. The duncan coral has grown to be a monster after about eight months in my fishtank. It has grown a few more heads since then. The most important part, each head has ballooned to be at least 3 inches across each with long sweeper tentacles up to 4 inches. 

Most people thought it is a colony of anemones before I explained what it is to them. I keep my duncan under 250W metal halide with 2X24W Actinic T5, 2X24W Colormax T5, and 2 strips of 12W Magenta and 420nm LED with moderate water flow. The one thing I have to say though, I feed each head half a shrimp (the kind you eat in your dinner) weekly, and they LOVE it! The only maintenance I have to do is actually trimming the sweeper tentacle that stings the surrounding corals. I use my metal tongue to just "snip" the extra long ones off.