some fish are sensitive to newly set up tanks as the water parameters may not be stable and the filter even though cycled will not be mature. its recomended to wait about 6 months before adding any sensitive fish as by this time the tank/filter will be fine and mature. neon tetras, rummynose tetras, blue rams, shrimp etc etc all fall into this catagory and if added to a new set up may well end up sick or worse.You know when people say you shouldn't add these to a new tank, do they mean to cycle it or adding them after you've cycled is still a no go?