Before Relativity, Einstein proposed that all energy regardless of type is the same. To illustrate this, he correctly predicted that when light strikes a metal, that metal will release electricity because energy is interchangeable.
Light (photons) can infuse metal atoms with more energy than they can contain, forcing them to release electricity (electrons). He called this The Photoelectric Effect.
This phenomenon ultimately became the technology in digital cameras, solar cells, and most likely in the screen that you’re reading this on.
When we first observed that Reverse Respiration killed algae more quickly in the dark, we finally understood how Reverse Respiration acts as an algicide. We used Einstein’s Photoelectric Effect to demonstrate how Reverse Respiration kills algae.
Reverse Respiration kills algae by removing electrons from metals in the algae. As seen above, the metal most affected by Reverse Respiration is magnesium. However, it also destroys the potassium and calcium amongst other metals inherent to a common alga's chemistry.
The “Lattice Energies” indicate the ability of each metal listed to enter into a chemical reaction. The greater this energy, the more likely a chemical reaction with that metal will occur. Of some metals commonly found in algae, magnesium followed by calcium are the most likely to form new compounds. This reaction can be catalyzed by a chemical reaction (such as the CO2 solution), electricity or light.
When we first observed that algae perished more quickly in darkness, we realized that light (photons) was interfering with this algicidal reaction.
The reason this occurs has nothing to do with photosynthesis, however. This reaction is about 10,000X stronger than photosynthesis.
Light degrades its algicidal power due to The Photoelectric Effect. In essence, if photons (light) are present, the energy required (electrons) to effect a chemical reaction may not all be taken from the algae, but rather from the light itself, sparing the algae to some degree.
If Reverse Respiration is performed in total darkness, the only energy available for this reaction must come from the algae, killing it.