Hi

I am new to sourdough and am struggling with hydration math!  Can any kind poster help me with a few dumb questions?  I have an established white starter at 65% hydration.  I have not yet baked with it and am now ready to take the plunge.  For my chosen recipe (Emmanuel Hadjiandreou's Seeded Sourdough) I require 160g of starter.  Can someone tell me how to build some starter for baking at 65% hydration (2 feeds at 12 hour intervals?) to arrive at this 160g.  I know, I'm dumb!!  The recipe does not specify a particular starter hydration.  Also, is it possible to change the hydration of my mother starter, and if so, how would I do this?  Or can I just bring the hydration up as necessary for different recipes?  I have a new rye starter currently under way, which is 100% hydration.  Don't want to end up with a frig full of different starters.

I am boning up on hydration, having just come to grips with bakers %s.  I will get there.

Thanks to anyone who is willing to help

Sondra