Did you read that article I posted a few days back? Having a diatom bloom is a good thing at this point. This falls in with what I was saying before - don't chase issues. Let it happen, it will go away on it's own eventually. Diatom blooms on a new system are inevitable, don't fight it.
You might get dino outbreak as well. IMO and IME dinos are a result of bacterial colony imbalances. This can happen when you disturb the system too much, and this can happen when you do some seemingly non-disturbing things like flipping rocks, rearranging rocks, changing flow patterns, changing lighting types or photocycles, etc...anything that causes a bacterial colony to either die off or burst in growth. There are many different bacterial colonies in play and for the next 3-6 months, they're going to be fighting each other in the background (this is one of the things that you can't easily test for).
Then will come the algae outbreak. Again, this is nothing you are doing wrong if and when this happens. Part of the cycle.
Messing with things (or "chasing issues") just makes this worse and/or harder to pinpoint. Focus on water parameter stability.
On water changes, there are a few schools of thought here. Large (30%+), frequent water changes are kind of like a "shock" to the system, when compared to smaller and less frequent changes. Large PWCs should be reserved for when needed. Small PWCs (10% a week, 20% every 2-3 weeks, etc) help refresh trace elements. Alternatively you can dose trace elements, but sometimes nothing beats a little new water on a regular basis.
