Gobardhan Sahoo These two links may help......Mark Nienaber, Northern Kentucky University, USA------Link= Algae.NKU.edu...... Please see the contact page ([email protected]).....The 2nd link is more general but shows the magnification need to do a count..........From Montclair University, USA.....https://www.montclair.edu/water-science/freshwater-cyanobacteria-of-new-jersey/visual-guide-to-cyanobacteria-in-new-jersey/coccoid/colonial/merismopedia/