Bristle Worm Problem in Seahorse tank

I will start here i have a column tank so it is built vertically (tall) for the purpose of sea horses as they love to go up and down in the water column and hang onto anything around them (i use fake SPS).

I added some Chaeto to the back end of the tank in each corner. When i feed the extra food sits in the Chaeto, this built the problem of bristle worms.

My question: Can i add an arrow crab in this tank? will he nip at the sea horses or leave them alone?

Any better invert to get rid of bristle worms? I thought about adding a leopard wrasse or something different that would eat them as well. But i really like the sea horse only type of tank for feeding purposes.