If you are having "all kinds of weird algae" showing up then your water is not perfect. If you are using HOB
filters with carbon in them how often do you change out the carbon?
How often do you do PWCs? What kind of source water are you using? Tap? RO
? Getting it from your LFS
? What are you readings when you tested your water? For algae to grow there have to be nutrients in your water, phosphates, NitrAtes, something is causing it. Diatoms aren't anything to worry about, I still get them in my tank and its been up for 2 years. That happens. As for the cyano
there is an issue somewhere and my guess is poor source water, and or filters needing cleaning. If you are using carbon in those filters then you will need to change it out weekly. After a week it is pretty much useless and they filter is just collecting muck.