The most common type of algae in a newly setup aquarium, hands down, has to be the infamous brown diatoms. When you first setup your aquarium, did you ever have a bad break out of this brown algae? If not, what did you do so differently to prevent this?
I never really experienced this outbreak due to my first few tanks being heavily planted (and thus taking any excess nutrients in the water column and using it as food for the plants). A few other tanks I setup that weren't using real plants never had such outbreaks due to them either not having a good lighting period (used a dim LED light, didn't have the lights on for an excess period, etc.) or due to me making sure that I never overfed any of my fish or shrimp (and therefore the tank not having any excess waste in to feed the algae with).
The only time that I had a horrible outbreak of brown diatoms, is when I was breeding African Dwarf Frogs in a 20 gallon long aquarium. I'm not sure if it was due this also being the first time that I had used Fluorite as a substrate (the tank was mildly planted), or if it was due to the waste that African Dwarf Frogs produce when they can't find food directly in front of them (used to put it on a plate in the tank), or when they shed their skin. The tadpoles used to love eating some of the brown diatoms that would stick to the floating aquarium plants I had, although I had to have a small cleanup crew of snails to make sure that it never got out of hand (once I cleaned the aquarium out from the outbreak I got and added way more plants).