Small tank = lots of water changes
I’ve run nanos for years... both dosing and not. IME, dosing is unnecessary for a tank that small. RedSea Coral Pro, Tropic Marin Pro (Great stuff but pricey, so if you’re saving by not dosing it’s well worth it) and Ocean Life Reef Crystals all have the additional trace elements added that you’re looking for without having to dose the aquarium. I’ve done 10-20 % water changes weekly and never had any issues. I run no filter media or skimmers in the tanks so I get max efficiency. Plus, I don’t max out my bio load by overstocking my tank or over feeding... That said, IF you do decide to dose the tank, Seachem Complete is great for the tank, easy to use (twice a week, 5ml per 20g), and has never caused any swings, losses, or outbreaks/blooms. I only dose to speed growth and enhance colors... other than that, regular weekly water changes and the occasional reefroid feeding will keep you where you need to be