@DazRunner@mastodon.social @lisamelton@mastodon.social so first of all, to be clear, the only algorithm involved in Mastodon and other ActivityPub software is "all posts, in reverse chronological order". the different timelines just vary in where the posts come from.

when you say "your feed", I assume you mean the local or global timelines? this is something that varies a bit by instance. the global timeline will always be a wildcard because it includes every post that your instance knows about in the entire fediverse (that has its privacy set to public, at least).

the local timeline is posts from people on your same instance. unfortunately, if this is the one you mean, mastodon.social is somewhat notorious for being infested with low-quality and bot accounts and having poor moderation. some users just block the entire instance for this exact reason.

@lastofthem@mastodon-belgium.be @lisamelton@mastodon.social Misskey antennas are basically this. You can pick specific users and/or keywords to include or exclude.