Tenax,

I am somewhat suspicious of your head calculation.....it seems quite high.

Mark (mas985) is the guru and I'll bet he sees your post and replies. He has a "rough" formula you can use to get pretty close on head.....I'm gonna' make a stab at remembering it.....I disavow all responsibility for getting it right!

Take filter pressure x 2.13 and add 10 for the suction side resistance. So, assuming I've got that right, your filter pressure would be 46psi.....I don't think a pool pump can get there.

In any event, I am clearly not a good resource for a definitive answer. Others will hopefully bail me out soon.