What are you using to test your pH? That is way high, starting to get into the harmful areas.
The diatoms, normal, nothing anyone can do to avoid that stage and usually happens the worst at months 1-3 after setup. Hair algae, ugh, hate that stuff now. A million different methods to help with that, none of them seem to be 100% successful though from my trials, ie, someone will tell you Turbo snails will solve it... they will help, but not solve it. You need to do several different methods to get rid of that, and one of the best methods I have read about, but not tried myself, is get a bottle of Kent Tech-M and dose until you get your magnesium levels above 1500. From everything I have read, it isn't the magnesium actually doing to problem solving, there is some other ingredient in Tech-M that seems to rid the tank of hair algae once you get magnesium above 1500. If you use any other type of magnesium supplement it doesn't seem to work from all the reports I have read on it. For me, I was fed up with it and just took out my rocks and scrubbed all the hair algae off with a toothbrush because I was tired of dealing with it.