If you are getting mould/algae growing, you are watering too frequently and the soil is over wet for too long.
Giving a deep watering to run off every few days is far better than giving small amounts of water often.
Only water again once the top inch or so has dried out.
You can break up the algae and let it dry out, this will kill it, but if you are really worried, you can scrape it up and remove it and then replace that layer with fresh soil.
Your plant does not need feeding yet, there should be enough goodness in the soil for another week or three.
Hope this helps, Organoman.