Phantom Tetras Being Bullied!

[f1sh]

My 2 phantom tetras were practically unnoticed by my male betta until i fed them some frozen bloodworms just now. Since then he had been chasing them and really flaring at them but they are much faster than him so he hasnt caught them yet. Im worried about what will happen when he does or if they get stressed. Im quite confused as they got on fine before and ive literally just told someone about how good they have been together! I have quite alot of neon tetras now so i thought maybe my betta might be a bit intimidated by all of the neons and now the phantom tetras?LFS recommended them together as well. Any ideas?

 

[Duck and Dive]

How big is the betta?

 

[Lateral Line]

Phantoms are a naturally shoaling fish, they should be kept in groups of say 6, preferably more. As for the Betta, you'll probably get better answers on the Betta board as it is more a Betta question then a Phantom one.