Viscosity 0,53cSt have no influence for performance curves
f(Q)=H.
By the way to appoint correction factors You must take BEP (Best Efficiency Point) only.
Generaly viscosity have influence on performance curves about 4 - 6 cSt. It depend for specific speed
Sorry for my ENGLISH
I understand more but I don't speak english very well
Page 11 corrects for specific gravity differences. On page 23 is a viscosity correction chart. But usually anything less than 10 cSt doesn't need a viscosity correction factor.