Post by Carl on Oct 8, 2022 18:49:46 GMT -5
Recommended Reading from Aquarium/Pond Answers libray
www.aquarium-pond-answers.com/2012/03/pur-vs-par-in-aquarium-lighting.html
OVERVIEW:
"This article is to understand how we can achieve optimum lighting for growth of a photosynthetic organism in our planted freshwater & reef aquariums, while considering having a limited artificial energy source, like a aquarium light fixture. We know we cannot create the amount of useable light the Sun gives, so we try to optimize the light we are able to make for a given about of watts (input energy).
I should note that a lot of aquarium lighting use history has gone into this subject, as we already know based on use of "warm white" fluorescent shop lights in the 1970s that we can grow plants, just not as efficiently as the lights we have now (Advanced reef keeping was not even possible with the available lights then).
So for some aquarium lighting experts to dismiss subjects such as the concept PUR as "theory" I have to respectfully disagree and I would state that this is showing a lack of knowledge or experience of the history of aquarium lighting.
We know that many man made white sources will grow plants, how well depending upon the PAR at the level where the plants are located (PPFD) and the efficiency of the often limited light energy we can provide (PUR).
However, we also know based on aquarium lighting history that when tri-chromatic, actinic and other "tuned" spectrum light sources were employed, in other words PUR, we did a better job growing these plants and eventually photosynthetic corals, etc. with the same exact input wattages.
Example: 40 watt warm white versus a 40 watt Trichromatic or a 40 watt cool white versus a 20 watt trichromatic plus a 20 watt actinic for anemone aquariums
In the end, we know that long before the advent of LED lighting, improved PUR would provide more light energy for the same given input energy, which is why along with other efficiencies (including drivers, etc.) the many economy LED lights such as the Finnex require as much as 4-5 times the input wattage as a better higher efficiency LED, often making any up front savings go out the window."
