Question: Oxygen generation in aquatic plants

[Cactuspete8]

We are doing an experiment in our lab course generating oxygen in Chlamydomonas
and measuring it in solution with a dissolved oxygen probe.  The problem
is our
lab techs have trouble growing Chlamy.

Does anybody do this with aquatic plants?  I would like to be able to buy
something every semester and have it work...The obvious problem is that most
aquatics store their O2 in lacuna...