I am at the very beginning in understanding light for aquatic plants, so any criticism is welcome.
First: lumens per square meter is a LUX and is a measure of light intensity as it is perceived by human eye. Plants are different. Plants don't need full spectrum of light for their photosynthesis. That's why we have PAR (photosynthetically active radiation) to measure what's important for plants. Further complicating things is that light travelling through water (quite different than air) is losing PAR faster as the distance from the source increases.
New T5HO lamps, are designed to emit more in the red (650-700 nm) and blue (440-490 nm) out of the entire spectrum (400-700 nm). Therefore , T5HO make better use of less light. T5HO fixtures uses reflectors to redirect wasted light into the water. Led light does not need reflectors or ballast, uses less watts and lasts longer than T5HO.
First: lumens per square meter is a LUX and is a measure of light intensity as it is perceived by human eye. Plants are different. Plants don't need full spectrum of light for their photosynthesis. That's why we have PAR (photosynthetically active radiation) to measure what's important for plants. Further complicating things is that light travelling through water (quite different than air) is losing PAR faster as the distance from the source increases.
New T5HO lamps, are designed to emit more in the red (650-700 nm) and blue (440-490 nm) out of the entire spectrum (400-700 nm). Therefore , T5HO make better use of less light. T5HO fixtures uses reflectors to redirect wasted light into the water. Led light does not need reflectors or ballast, uses less watts and lasts longer than T5HO.
