filter feeder they are fine. If you go to the link and look at pineapple sponge they tell you suitability. Also has remarks section under the particular hitcher which provides further information. Really a nice link
+1 pineapple sponge, they will multiply like crazy generally in your filtration area (sump/rear chambers in AIO). My rear chambers in BC29 are covered in them and never had any issues with them.