To answer this question, we have to go back to the fundamental functioning of a fish light. While we would like to think these lights are magic, there is a simple scientific basis to them. When a light is placed under the water, it reflects off particles in the water that attract bait fish. These bait fish attract the predator fish in the area. The predator fish, or game fish, you might see are snook, tarpon, redfish, lady fish, and many more. These lights work the exact same way in fresh water as well, where you might see bass, crappy and carp.
When thinking about the brightness of a fish light, there are many things to consider. You must first consider the type of light you will be using. Some fish light companies use LED lights for their dock systems. While LED lights are relatively bright compared to typical lights we, as consumers, are used to, they are not always bright enough to light up a large area by your dock. LED lights also do not generate heat; therefore, they are unable to clean themselves. This will lead to excessive aquatic growth, like barnacles and algae, to build up on the light in the water, and eventually render the light useless. To recap, LED lights struggle in two ways; they are not very bright, and they cannot clean themselves.
The best type of light for permanent dock installation are HID lights. These bulbs are not only over 300% brighter than LED lights, they are also self-cleaning. These bulbs generate enough heat to burn off any aquatic growth that tries to grow on the bulbs. Because of this, high-quality fish lights run on a photocell, which turns it on each night and off each morning. This ensures the light will turn on all night, every night, to it can remain clean and barnacle/algae free. The photocell also builds a feeding cycle for the fish, teaching them that each night they can find food by your dock, so they will keep coming back.
Once establishing the type of light you will need for your dock (which is always HID!), you will need to decide what wattage of bulb you will need. This will depend on the clarity of your water, as well as your personal preference to the amount of light you want. There are two levels to choose from. The 175-watt Natural Green light is the entry-level bulb size that gives, on average, a circle with a diameter of 10 feet. This light works great for customers with crystal clear to mid-clarity water. Obviously, there are many customers that do not have clear water. Because of this, 250-watt bulbs are available. These bulbs are 50% brighter than the 175-watt lights and over 400% brighter than LED lights. The 250-watt Vibrant Green light gives, on average, a circle with a 15-foot diameter.
There is one fact that is incredibly important to know; there is not set standard for every dock. For some customers, the 175-Watt Natural Green light gives a substantial amount of light and brings in hundreds of fish, but for others that might have dark water, the Vibrant Green is the only way to go. That being said, you obviously do not need to have dark water to warrant a Vibrant Green 250-watt light. Many customers want to cover the most amount of water possible. Because of that, they purchase the 250-watt Vibrant Green bulb and are extremely happy with the results.
Choosing the right Underwater Fish Light is not am exact science. It all comes down to what you, the customer, is looking for, and which light can fill that need. There are two things to ask yourself; “What is my water clarity?” and “How much light do I want?”