What's your Lightings intensity

[Simon]

120x45x45cm
65.7 USG
6x36watts PL - 3.3WPG

180x60x60cm
175.1 USG
2x150watts MH - 1.7WPG

[Fei Miao]

1)Tank size : approx 20 gal
2)total wattage of lights. 72watts
3)watts per gallon. 3.6watts

[naturetan]

Vincent, that's a valid and interesting thought you have.

It seems like when we take into consideration of volume measurement, we're considering the light penetration through the depth of the water. But when we take tank surface base area for our calculation, we assume that water is of complete clarity and the factor of liquid matter opacity is omitted. I think the latter is more accurate in approximation for average depth tank, since most of us keep clear water.

My tank is still consider low light for standard 2ft tank, using surface calculation, and 2Wpg for volume calculation. At such rate, riccia will still bubble without the need to increase. However, I believe another very uncertain factor we still need to consider, is using what type of lighting. PL and FL has very different intensity. My plants react quite differently under this 2 lighting. From my observation from plants, PL are much stronger than FL.

Hmm.. How much stronger is actually PL compare to FL? If anybody knows.