System pressure help

[sebasendallas]

hi guys , i have a in ground pool 40000 gal, with a 1.5 hp pump and a hyward 4 cartridge filter , have 3 returns to the pool , one cascade and 3 jets that spray the water high .when i run the pump throw the returns the pressure is 10 to 15 psi , but when i change to cascade or jets raise to 40 45 psi . is that normal ?? thanks