1. Rich reef snobs. rich people who think you are not a reefer unless you buy the most expensive equipment.
2. People who buys $100 frags and think they should sell them for $100 as well. Basically selling frags at diver's den prices (as if they have brick and mortar store overhead) without the diver's den guarantee.
3. Reefers who think they are "entitled" and arrogant. you see a lot of those in the other big board, some got banned and moved to you know where.
4. The reefing oxymoron, people who sells micro frags, or even nano frags of corals that grows like weeds, yet asking for an arm and a leg for it. example, red planet.
5. Internet/google reef experts. I have seen people try to answer every single question posted via a google search result, and very little of his answers come from actual experience. The internet has made a lot of instant experts, not just on reefing.
6. I am all for supporting LFS, but not if they are literally robbing you blind with the price they charge.
7. I have been flaked by buyers and sellers. Buyers that flake don't bother me as much, as I think that should be treated as part of selling. what bothers me is seller pm's me at the last moment saying he sold the item to someone else.
8. People who joins the bandwagon for whatever is currently being hyped, then claiming their corals are happy and that they can actually see corals started growing bigger right before their eyes, etc. immediately after pouring in the additive, or installing the equipment. I don't mind the joining the bandwagon part, but let's be realistic with the results.