I can now only get 2mil Perlite not 4mil for my potting mix. Will 2mill be ok.?

So if anyone makes up there own potting mix do they know if the size of the Perlite makes a difference, I know it may seem an odd question but you read allot about getting things right in the pot, air ratio water retension and drainage etc and with the 4mill Perlite I seem to have struck lucky, now I worry will the 2mill be the same. thanks.