It shouldn't, if you rinse it well before you put it in the tank and let it settle for a couple days before you add your betta. If this is an established tank, it may also be good for you to rinse out your filter media in used tank water once the cloudiness clears up a good bit. You'll find a lot of particulates in your filter media.
I have found ecocomplete to be less dusty than any other media I've used, except for smooth gravel, which is pretty useless for a planted tank.
Beth, mom of two humans, and caretaker of eight cats and seven bettas. Yes, I'm crazy.