Low - Med - High wpg rates

[mitche8359]

I've been looking for a chart or information on what is considered low, med, and high amounts of light on a wpg scale. Seems to be differing views. One one site, 2wpg is low but the same 2 wpg on another site is medium.

I have found a couple high-average light plants that I'd really like to get but don't want to waste the time and money if they aren't going to grow. I have Micranthemum umbrosum growing in the tank which is listed as a high - very high light requirement plant. However, the plants have been sending out water roots which to me is saying, hey I'm growing.

Another plant that I'd like to get is Heteranthera zosterifolia which is listed as the same light requirement.

[debrab1954]

i have been wondering the same thing

[BlueRam]

A place to start thinking about WPG and the exceptions is at:
http://rexgrigg.com/mlt.htm

Basically WPG is so arbitrary. Other attempts such as light/area have been proposed to replace. Rex frames lux per square inch for example.

So mitche8359, 2 X 55/65W PC (same lamp, different hype) with good reflectors puts you in medium/low at ~2WPG. There are a fair number of plants that will do fine including some that "should not" as you have found.

The distinction is that at higher light (> ~2.5WPG), adding CO2 and nutrients will become important (others will state that you should be doing it now). When you get up to > 5 WPG you really need to stay on top as growth is explosive!