Homemade PCB Photoresist Developer?

This site has GREAT 'ibbles for ways of etching and transferring toner to PCBs.  I still use photoresist and would love to know if anyone has a recipe for homemade developer.  I know its mostly Sodium Carbonate, but there's some pH nonsense that needs to be addressed.  Any help would be greatly appreciated!!

Here are some specifics for you.

http://www.pcbfab.com/developing