Aquatic Plant Central - View Single Post - leaving CO2 during the night.. controlling algae

rhodophyta · 05-19-2009, 02:05 AM

I did some reading on photosynthesis and found out that contrary to popular wisdom, all vascular plants absorb CO2 at night and that some plants including many desert plants, bromeliads and orchids only absorb CO2 at night and don't during the day when it is warmer and would take more of an energy investment. Since most or all of the aquatic plants we keep absorb CO2 24/7, it seems logical to supply it that way.

What I read explained there are two steps in photosynthesis. The first uses light to obtain energy, sort of like charging a hydrogen fuel cell, producing oxygen as a waste product. The second step uses that stored energy and the CO2 in the plant's tissue to create sugars, does not need light and goes on 24/7 even in plants that don't absorb CO2 in the day, relying on the CO2 absorbed the previous night. It would seem like if there were any time to stop injecting CO2, it would be for a while during the light period when the vascular plants might have an advantage over algae.

05-19-2009, 02:05 AM	#5 (permalink)
rhodophyta Senior Member Join Date: Jan 2006 Location: Brunswick, Ohio Posts: 100 iTrader Ratings: 0 Plant Points: 9250	Re: leaving CO2 during the night.. controlling algae I did some reading on photosynthesis and found out that contrary to popular wisdom, all vascular plants absorb CO2 at night and that some plants including many desert plants, bromeliads and orchids only absorb CO2 at night and don't during the day when it is warmer and would take more of an energy investment. Since most or all of the aquatic plants we keep absorb CO2 24/7, it seems logical to supply it that way. What I read explained there are two steps in photosynthesis. The first uses light to obtain energy, sort of like charging a hydrogen fuel cell, producing oxygen as a waste product. The second step uses that stored energy and the CO2 in the plant's tissue to create sugars, does not need light and goes on 24/7 even in plants that don't absorb CO2 in the day, relying on the CO2 absorbed the previous night. It would seem like if there were any time to stop injecting CO2, it would be for a while during the light period when the vascular plants might have an advantage over algae.