So when my 120 crashed and i traded it for a downgrade i was able to save some of my lps and give them to my father in law who has a 125gal reef which has been established for at least 3yrs everything is doing fine in there he does things a little cheap but its been working for what he has but one of the corals that i had him save for me was a beautiful green and purple wellso it was my favorite that i had at the time and it was growing great in my old system and was in his until the last few weeks it has been loosing its color and turning white its on the sand bed and as far as we know nothing (fish or invertebrates) are pestering it, it has been in his system for several months previous to this and was thriving he also has a red wellso he got from tpa and its not losing color its thriving and none of his other corals are losing color he has a mixed reef with sps, lps, and softies his sps are nothing fancy and dont have great color but are growing and have good polip extension as does all his other corals his water parameters are fine he tells me and he checks regularly and did when the problem happened and continues and states that the water is good so please refrain from comments about what the parameters are at because i dont know specific numbers his lighting is t5 nothing fancy just oddyssea brand and only 4bulb it reaches the whole length of the tank for all is lit, but i know this wellso shouldnt need much light but that was my first guess but nothing else in that area or anywhere else in the tank is losing color and the bulbs are only a few months old so sorry for the long narrative but i love this wellso and want it to regain its former glory and would love to understand what is going wrong oh and also he does feed from time to time nothing bad or much thanks for all the help