how bad of a temp swing could cause an issue? I live in rural australia and my tank can swing from 24°c to 28°c in 12 hours. Thanks for the reply!Some causes can be often a change in salinity, temperature and salt mixes. Additionally, Elevated phosphate, light and even new light and elevated alkalinity levels will be a higher risk to coral. Other minor factors will be low Dissolved oxygen, new corals especially leathers (which emit a toxin known as Terpenes), false test kit readings and newly added rock can alter chemistry.