Hydration difference between soft wheat and durum wheat

Hello all,

My regular pizza dough recipe has a combination of wheat flour (somewhere between A/P and bread flour), whole wheat flour, whole rye flour and a bit of whole corn flour (see percentages below).

I got some durum wheat now and I'm not sure what to do with the hydration of my formula when changing the wheat flour to durum wheat. I have big batch of pizza's (as you can see :-) for a family reunion that I'm making this weekend and I would like to use the durum wheat flour.

So, my question really is, when changing the 80% soft wheat to durum wheat, what hydration change would you make, if any.

thanks a bunch!!

Alef