It's a bit more complicated than this, but this is a simplified explanation:
at day 7 the transaction fees go up to ~1% average fee on every transaction. Those fees will be added to every block reward of 10 FRESH. For example: when a total of 5k FRESH was transferred in that block, the total reward of that mined block will be 10 + 50 = 60 FRESH.
If there is (really) need for it I will adjust the transaction fee percentage.
you'r talking about PoS blocks, right ? I saw 7 days PoW at the first page.