Every time I put in new shrimp whether they be coral banded, cleaner, or peppermint I can’t keep them alive. I also have an issue where I lose about half of my snails. I don’t think it’s iodine or copper, as I have had two shrimp stay alive for months now, my tiger pistol, and one peppermint shrimp which always hides and I assume it’s dead. Usually, when they pass it’s slow, they either become lethargic and stop eating and the next day they die, or after a water change they swim erratically then die overnight, or they disappear completely. No other issues at all besides GHA, which is why I keep adding more snails over time slowly. I also dose all for reef every other week using tropic Marin salt.