Watts per Gallon, Big Tanks vs. Small Tanks

Re: Watts per Gallon, Big Tanks vs. Small Tanks

It's a rule of thumb thing that doesn't work well when talking about very large or very small tanks. I can't say I know the orgin, but it does work for tanks from 10g on up to what, 200 or 300 gallons? Maybe more?

On the small end, it can get perty ridicules. I have a 3 gallon Eclipse on my desk. It has a 6 watt T5 light. Six watts of light isn't very much at all for growing plants. The rule of thumb says I've got two watts per gallon and should see some impressive plant growth. I consider it a low light tank and see hardly any growth at all. The Anubia has sprouted two leaves in 5 months. The Java fern is about the same size. The Ludwigia is thriving, but it has very slender leaves compared to the same plant in my large tank at home.

If you had a quart jar full of water, could you grow high light plants in it with a 1 watt light? After all, that would be 4 watts per gallon!!

steve

 

Re: Watts per Gallon, Big Tanks vs. Small Tanks

I found this to be the case with the light unit I had not covering both front to back and side to side in my 20g. With one light on for 2X55watt pc unit plants were living not thriving. Turn second light on, spread of light is excellent and plants are growing... well like weeds ;-p

I can definitely vouche for this, my 75 gallon tall glass is still collecting dust due to how much of a pain it was to clean out. This tank if I recall was 36" tall and completely impossible, short of arm extensions, to work on anything in the substrate.


Ken