I have not seen them eat any FW
but I have read that the 6 and 4 line wrasse will help. My reef club member is using the nudi and it is working well for him in his reef. The only down side is that the nudi will die when the food supply is gone.
I know several guys who have used the FW
exit with success in reefs. Just remember you need to try and syphon out as many dead FW
as possible. I have a ton of them in my 20 fuge on my FOWLR
(came on some free caluerpa) I have not done anything to them yet, may try a 4 line wrasse when I find one.