Didn't see it answered but I believe the white speech bubble indicates a section where nobody has posted for a while or you have read all the related content available and there has been no new posts.
For mods and liquid check out the cracking thread provided by and maintained by @MrDJ as it will offer massive help... once you have found some stuff you like you can then post a new thread asking people's opinions who have used or bought them recently or do a search and see if the same question has been asked recently.