Reefing community is divided into two camps:
- Those who love spirobids
- those who hate them
Either way there’s no easy way to get rid of them, however as tank matures, they will be slowly replaced by other creatures, so it is another phase which will most probably resolves in few months. Meanwhile just clean your powerheads in. Vinegar or citric acid solution now and then and scrape spirobids of the glass.
One of my smaller tanks was full of them once, now I can only find them under the rocks.