Has your beardie had a vet check up?

Your set-up does sound fine. Where are you from?

Repti-glo 8.0 was discontinued a few months back. The tubes are ok to use though.

Do you have a flourescent tube or compact coil bulb?

The best UV Tube to use is the "repti-sun 10.0". Since i have been using this UV my beardie has perked up no end.

Your beardie is probably stressed as the other beardie was dominating him. He maybe needs time to adjust to being on his own. He will realise that he is not being dominated anymore and should be happier, and eat more