I'm going to be a giant bucket of cold water on you, in multiple ways. 

First, P-limitation does not really have a large effect on lipid accumulation.  The last time I did these tests with a former client with 20 or so strains the N-limitation effect was 10-20x more potent than the P-limitation.   Keep in mind, you are considering limiting a phosphate a key element in phospholipids

.  

Second, they are incredibly difficult experiments to pull off (measuring lipids is technically challenging- need a mass spectrometer)  and isolating p-limitation in a algae culture is difficult as bacteria (ubiquitous) will recycle P from the water.  And one more bucket,  just do it with ONE algae strain with a larger number of replicates (n).  

But I have to choose; Chlorella or Nannochloropsis.

Media:  You may want to make your own.  Check out our media recipes.  You are are looking at REPLETE and DEPLETE conditions.  Watch your P-ions from other salts being added.  All medias used with the weed algae strains can tolerate >10x normal nutrients.  Use this to your advantage when you limit P.   

To limit, give them a fraction of the P as they would normally need to grow the culture.  They will still require some.  

Probability of success:  If I were to do this myself, in my lab, with a 20-hour per week technician, I would give myself 10 weeks and a 80% chance of failure.  

A good project:  As a former resident of HB.  I suggest going around to the little bits of waterway and seeing if they are ripe for algae blooms.  Try this kit. 

Good luck!

Matthew