refreshing starter amounts?
So I have a starter made from the formula in Peter Reinhart's Artisan Breads Every Day. Currently it weighs about 250g (I've used twice), and it's been about a week since I made it. In looking over the book directions for refreshing, you use what seems to me a giant amount of flour and water! I don't want to keep that much starter around. His ratio for refreshing looks like 1 starter, 3 flour, and 2 water. My question is, could I simply add, say, 90g of flour and 60g of water to my existing amount of starter? I don't want to rebuild a huge amount, just keep it alive.