Low light plants

I was looking at WPG, I read that you take 10-15% of the size of the tank. so for my 30g tank....25.5 to 27 watts would equal 1 WPG, Is this correct?
If so, If I go with something in the neighborhood of 60 watts I would be at 2.2 to 2.5WPG.
 
Well technically a 30 gallon tank would hold less that 30 gallons of water when you count the gravel and such, but I always just go with the tank size when factoring in watts per gallon.
It's a loose rule of thumb anyway. The footprint of the tank, the type of lights and even the reflecters all affect the lighting quality.
What type of lights do you have?
 
I have 2 spiral CF at 26 watts each (6500k) both are in clip-on work lights from the Depot and 1 strip light that came with the tank I believe for now it is 17 watt all glass bulb that came with it.
It is just an experiment, I bought a few different plants to see what happens.
Water Sprite-growing like crazy
Java Moss- growing well
Wisteria-looking good
Compact Amazon- looking good
Foxtail- really pretty
Cacomba- Weird, bent over top is to big for the bottom
Micro Chain Sword. from what I've read this should require med-high light, nutrient rich substrate and CO2 and Iron supplements. If flourish and f. excel count as Co2 and Iron then I have one out of three...should be interesting to see what happens.
 
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