Planted Tank Basics - Lighting

Here is where the success or the failure of your planted tank can happen. Lighting is very important!!

There is a formula called "Watts Per Gallon" that can get you close to the target amount of watts you will need to grow most plants. Normally 2 - 3 watts per gallon will grow the majority of plants available that require "Moderate" light. Lets use an example tank... If you take a common sized tank such as a 55 Gallon and only use normal 2 x 40 watt Flourescents, and do the math, 80 watts total divided by 55 gallons you will find you are barely over 1 WPG... very little grows in 1 WPG other then Algae.

To get to 3 WPG in that tank you would need to at least double the amount of wattage input to get around the 3 WPG in that tank. If you used 40 watt NO Flourescents it would take 4 bulbs to get you to 160 watts which is more then sufficient. Since available space over a tank is always a concern with lighting , you need to get more watts in the same space. There are a few ways to do this and the most common way is via "Compact Flourescent Lighting also known as PL Lights". They are available in many sizes and can be used in combination with each other to get the amount of watts needed to grow your planted aquarium. Generally, lighting is usually on for 8 - 10hrs daily.

In the same scenario for the 55 Gallon, if you took and installed 3 - 55 W compacts over that tank instead of 4 - 40 watt flourescent, you would be at 165 watts total but your bulb intensity has gone from 40 watts to 55 watts with the pc's but you still achieved about the same in total WPG. You will get better growth from the 55 watt intensity even though you are only 5 watts higher in WPG.

The common wattages available for PL lights are 11, 13, 24, 36 or 55W.

The next big favourite lights used by planted aquarists today is T5 HO, its a slimmer version of your normal flourescent and its High Output. Such lights use electronic ballast that does not generate heat as much as iron-core ballast.

Advantges of T5:
- slim, able to fit more tubes over limited space
- individual reflectors which maximise light output
- does not generate lots of heat
- excellent light output

Although it will cost you a little more than your normal lightsets, the money you pay will last you a long time with a smile on your face too!!

My Recommendations for bulbs:
PL - Osram, Elbiru
T5 HO - Aquaz, Osram, DE

My Recommendations for light sets
PL - Jebo, Magnum
T5 HO - Solite, Jebo

Contact me if you have any further enquiries or need assistance
Feel free to post your comments too!

The WPG Rule is very general and some thought needs to be put into lighting choices before setting up your tank, but always keep in mind that plants need the "Watt Intensity of the Bulb" to be successful, as well as WPG.