Every once in a while check the pH of your runoff water. Eventually the coir may reach the optimal pH and you won't have to adjust so much.
Add the nutes first, then test, then add the pH up/down.
Do you know the pH of your tapwater? Mine is 7, my soil is just perlite and composted cow manure/leaf humus, haven't had any reason to adjust since I got rid of the peat moss in my soil mixes. It's one of the reasons I'm through with hydro as well, and avoid those 'soilless' mixes like coco coir. The leaf humus has a natural buffering action at around what you need to grow the shrek.