Need some help with browning out sps

[Aquattro]

Flow, to me, isn't that important for color. Or growth for that matter, if you're not concerned with thick natural growth. SPS in alow flow will grow very skinny and spindly, but will grow.
Lighting is important, not too much, not too little. Some nutrient is fine, many SPS tanks have some nitrate and measurable phosphate. As Levi said, stability is important, and tougher in a small tank. Not impossible, but not ideally managed by someone with less experience growing SPS. I've seen nice nanos with colorful acros, but I imagine it's much tougher.
Really, there's lots of ways to be successful and lots of ways to not be. The trick it to find that sweet spot for your setup and habits. All the info, together or in part will give someone a place to begin figuring it all out.
Daniella has shown pics of her corals and they;re impressive. I would be less quick to dismiss her advice.