If you have kits for nitrate & phosphate, you might want to cut back somewhat on your ferts and test a couple times a week to get a feel for how it's going to go. Depends a lot on how heavily planted you are, CO2, fish load, etc.
My 40 breeder with LED+ only occasionally needs a little bit of KNO3 to hold nitrate at 10ppm. I dose a tiny bit of phosphate and some potassium twice a week, iron & micros every other day. I've got a pretty good fish load and am moderately planted.
Nope, the stock sunset setting doesn't do a fade, you need the add-on ramp timer (or an Arduino controller) for that.