"Wendy" wrote in message news:sB23b.69617$kP.25605@fed1read03...
Just another thought on algae..........It is alive & growing, so it's using
up the oxygen
that the plants need? Yes?
Cheers Wendy


No. Plants use CO2 and give off oxygen as a waste product. Most of
the
oxygen presently on earth is the product of plant metabolism. (mostly
by marine plankton) Before oxygenating organisms evolved, Earth's
atmosphere was probably devoid of free oxygen.



J. Del Col