Tonight we talk about lighting.
Aquarium talk 101 by Geekzeke. Tonight we talk about lighting. Here is where the success or the failure of your planted tank can happen. The Aquarium Lighting supplied to you when you first purchase your tank is only intended for viewing your tank , the lighting is very much under powered to successfully grow a majority of plants in. 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 but needs to be fine tuned for some of the more demanding varieties of plants. Normally 2 1/2 - 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 the "supplied lighting" for that tank, normally 2 - 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". 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. 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 NO's 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. Another way to get more "intensity" from your Normal Output Flourescent bulbs is to do what we call "Overdrive" the bulbs through use of bigger ballasts. The idea is to use a ballast that is normally designed for either 2, 3 or 4 bulbs and apply it to one bulb giving the bulb much more intensity. I have done this with great success but prefer the Power Compacts due to safety reasons. Click Here for an in depth article on Overdriving. Also, there has been much debate risen over the WPG rule in regards to some of the smaller sized tanks. You may find that you have hit the 3 WPG mathematically, but you are still lacking the "intensity" of the bulbs in question. Note: I hate math. Example: Take a 10 gallon tank, by the math you could put 2 - 18 watt Normal Output Flourescent bulbs over it and have 3 + WPG "mathematically" but you still only have 18 watts of "intensity. You will not be able to grow many varieties of plants successfully in this tank even though you are at the 3 WPG that we are looking for. Now if you take that same 10 gallon tank and put a 1 X 36 watt Compact flourescent over it you now have the same amount of watts total but you have 36 watts of "Bulb Intensity" in which you can grow virtually any plants you choose. 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
