Sick goby

[Opticat]

I have a sick goby that might be dying, I can't feed him medication (metroplex because of the risk of other inverts eating it) also don't have qt, i don't see any white spots on him except for his bottom lip which has a white spot, he was fine for the past few days, but he started to be lethargic yesterday. What should I do? I try to target feed every time I feed the whole tank but doesn't seem to be interested on the pellets.
Water parameters are also good
Currently have 2 clownfish that doesn't seem to bother him, 3 Nasarius and 1 cleaner shrimp.

View attachment 2424957 View attachment 2424958

 

[Opticat]

Salinity is 1.025

 

[Ricksreeefs]

I’m no expert but have you tried frozen food? If you use a turkey baster you can spot feed him the frozen mixed with something like metroplex. I fed my fish metroplex when they got sick and I have a large cleanup crew and non of them died. If you have corals you just want to make sure that they don’t eat it.