I have a black box grow light LED off of Amazon. Has done fairly well: https://www.amazon.com/gp/product/B07312WKX2/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
I do have urchins, but they haven't touched it? Unless they just missed it. Unfortunately some of the bryopsis is in between coral so the urchins can't reach.