My Festae wont eat.

[Jakob]

After 7 years of fishkeeping this is the first fish that just WONT eat. This is a 3" Festae that i got 2-3 weeks back. I am keeping him in a 100g tank (60x20x20") with:
1x Convict male 4"
1x P. Senegalus 4.5"
1x Common Pleco 4"
1x Ropefish 9"

I dont see much problem with the convict but always when the con swims by the RT gets all gill flaring but the con doesnt even look at him. I have only once seen the con really care and gill flare for a few seconds.

My problem is that my festae just doesnt eat.
I feed:
Tetra flakes (for the convict and the festae)
Cut up Market shrimp (for the senegalus and the ropefish)
NLS jumbo fish Thera A+ (for the pleco and the polypterus)
Cichlid Chow (convict and festae. Either of them eats that so i stopped feeding it).
Should i worry?

 

[balton777]

I don't know what, if anything, is wrong but I hope everything works out for you.

 

[Jakob]

thanks Balton. He/she is getting more skinny, it is really stressed witch i think is the cause of it not eating, it has NO reason to be stressed, water params are good. WC 1-2 times a week.. Good filtering.
Rena Xp3 and Juwel 1000.