You will get paid every four hours using Nicehash platform, 550MH can do 18$ per day so use viabtc or 2miners pool, you will get paid once every day no matter how much you have mined, even if it's just 2$ you will get paid, do your own research.
Now ETH value is rushing down, so i think mining other coins should be way more profitable.
Which coin would you start mining today, to do the best profit with my gpus?