As we know, ammonia/ammonium and nitrites are highly toxic to fish and shrimp. However, when cycling a planted tank, it's very common to get pond snails and/or ramshorns in the tank, and they happily browse around and even breed in a cycling tank. Does this mean that snails are unaffected by the presence of ammonia or nitrite in a tank? I'm wondering whether it's worth adding in a couple of nerites to my currently cycling tank, as I think they'd enjoy the invariable algae spells that will appear.