anthius sick

Hello everyone. I'm brand new here. I've been stalking the forums for the last 5 months or so, and now it's time to post for some help. My tank is 5 months old. Here are the parameters. 130 gallon with a 30 gallon sump RODI water with 0 TDS Temp is 77.6 Degrees F Specific Gravity is 1.025...