Before power compact lighting was available, people on APD created a sort of watts per gallon guideline to serve as a rule of thumb for planted aquaria:
below 2 wpg ---> low light
2-3 wpg ---> moderate light
3-4 wpg ---> high light
This guideline was created at a time when normal output flourescents with white paint as a reflector were the norm. Somehow, this watts per gallon rule stuck in the planted aquarium hobby despite considerably advances in lighting technology. Many newcomers to the hobby believe that they need 3 or more wpg to grow a wide variety of plants --and this is not true, especially when they are referring to 3 wpg of power compact lighting with good reflectors (such as AH supply's). I believe that hobbyists in the US, as a result of continuing to apply these rules to power compacts and VHOs, use considerably more light than many other foreign hobbyists with equally successful aquariums.
My experiences:
I started out with 2x55w power compact lights from AH Supply. On my 55g, they provided exactly 2 wpg according to the rule as a recommendation from Erik Leung. He told me I could grow anything with that amount of lighting. He was right. During that time, I grew Rotala macrandra, Rotala wallichii, Heteranthera zosterifolia, and Alternanthera reineckii in very large quantities. The plants grew in large and lush. I was very pleased. When I tried Glossostigma elatinoides, again using his advice, I planted the runners horizonatally into the substrate. The Glossostigma grew as flat as any glosso foreground I had seen in books or on the net!
During the first year that I was away at school, I left the tank with a single 1x96w power compact light on my 55g. I did not believe that anything would do well with such "dim" lighting levels. When I came back for winter break, I was astonished. The Bacopa caroliniana was large, robust, and pink. Hemianthus micranthemoides grew as a beautiful, compact mound (I wish I could get it to grow as well at higher light levels where the individual stems tend to become smaller and a little rattier). The grouping of Ludwigia repens grew as a beautiful large specimen taking over 1/3rd of the tank. After seeing this, I dared to try more species --Proserpinaca palustris, Didiplis diandra, Lysimachia nummularia, Alternanthera reineckii, Rotala wallichii. They all did very well and were as healthy as any plants I've had in my "high light" tanks.
There was one problem though. The dense growth at the middle and top layers kept shading the bottom so that nothing could prosper there. Solution: I planted the substrate with Cryptocoryne wendtii 'green', Anubias barteri v. nana, and Cryptocoryne wendtii 'red' to cover up the substrate and bare, leafless lower stems. They also did well in their respective places...
So, should the wpg be shifted downward to reflect the greater efficiency of aquarium lighting today? Should 4 wpg be recommended to newbies wanting to grow a large variety of "high light" plants? Should we start recommending 1.5 wpg to people who just want to grow crypts, ferns, and Anubias? Why or why not?
Carlos
below 2 wpg ---> low light
2-3 wpg ---> moderate light
3-4 wpg ---> high light
This guideline was created at a time when normal output flourescents with white paint as a reflector were the norm. Somehow, this watts per gallon rule stuck in the planted aquarium hobby despite considerably advances in lighting technology. Many newcomers to the hobby believe that they need 3 or more wpg to grow a wide variety of plants --and this is not true, especially when they are referring to 3 wpg of power compact lighting with good reflectors (such as AH supply's). I believe that hobbyists in the US, as a result of continuing to apply these rules to power compacts and VHOs, use considerably more light than many other foreign hobbyists with equally successful aquariums.
My experiences:
I started out with 2x55w power compact lights from AH Supply. On my 55g, they provided exactly 2 wpg according to the rule as a recommendation from Erik Leung. He told me I could grow anything with that amount of lighting. He was right. During that time, I grew Rotala macrandra, Rotala wallichii, Heteranthera zosterifolia, and Alternanthera reineckii in very large quantities. The plants grew in large and lush. I was very pleased. When I tried Glossostigma elatinoides, again using his advice, I planted the runners horizonatally into the substrate. The Glossostigma grew as flat as any glosso foreground I had seen in books or on the net!
During the first year that I was away at school, I left the tank with a single 1x96w power compact light on my 55g. I did not believe that anything would do well with such "dim" lighting levels. When I came back for winter break, I was astonished. The Bacopa caroliniana was large, robust, and pink. Hemianthus micranthemoides grew as a beautiful, compact mound (I wish I could get it to grow as well at higher light levels where the individual stems tend to become smaller and a little rattier). The grouping of Ludwigia repens grew as a beautiful large specimen taking over 1/3rd of the tank. After seeing this, I dared to try more species --Proserpinaca palustris, Didiplis diandra, Lysimachia nummularia, Alternanthera reineckii, Rotala wallichii. They all did very well and were as healthy as any plants I've had in my "high light" tanks.
There was one problem though. The dense growth at the middle and top layers kept shading the bottom so that nothing could prosper there. Solution: I planted the substrate with Cryptocoryne wendtii 'green', Anubias barteri v. nana, and Cryptocoryne wendtii 'red' to cover up the substrate and bare, leafless lower stems. They also did well in their respective places...
So, should the wpg be shifted downward to reflect the greater efficiency of aquarium lighting today? Should 4 wpg be recommended to newbies wanting to grow a large variety of "high light" plants? Should we start recommending 1.5 wpg to people who just want to grow crypts, ferns, and Anubias? Why or why not?
Carlos