Need refugium help

[maron6977]

It's a section in my sump , approx 10-15 gal. I use 2 reactors to feed it , hydroton & carbon . Just swapped out to LED with pink hue . Have couple pieces of extra live rock & Cheato ball . Always found my refug to grow nuisance algae , mainly cyano. Nitrates a little high , ranging from 5-20 ppm. I feed a lot & think'in to put a deep sand bed in there with Cheato on top .
Input please
Mark