Welcome bro to world of reefing.As your tank is just a few months old, don't fess up by those diatoms. It will generally clear by itself when the tank matures which can take about a year. The word is not to panic into doing something stupid.
As for maintaning water quality, do have a schedule and stick to it.There are many ways to go about this and often than not beginners don't read enough for their own good. Instead they fully rely on the other reefers.What works for one doesn't mean it will work for you.I am sure you can find lots of info from books and internet.
Much said, hope you will enjoy this hobby.Cheers.