I have a 315 gallon reef tank with A variety of euphyllia, acans, zoanthids, and sps such as acropora and montipora that are all doing great. However for some reason my GSP and Kenya tree that I have had in the tank for a while have died for no apparent reason. This is very confusing considering they are very easy to keep compared to the acropora I have in my tank that is doing great. If there is anyone that has any idea why this is happening please let me know.