using coir with soil , and a question about foxfarms

I have been looking for a coir pre mixed soil as this is my first grow , but i cant find it . I have decided to make my own , but cant find coir to add to soil . How fine would i have to shred a block of coir to add it to the soil ? I plan on using it with foxfarms soil , ordered some off of ebay but some one told me that the soil will not pass the canadian customs , is this true?

You can try roots organic 707 lovely soil. Not sure but Why would costumes be worried about soil I don't see Why they wouldn't let it through.

have u had any problems with gnats as i have been reading so much about with this product ?

Not problem with them, I started with miracle grow and then regular roots organic now 707 roots organic. I think I'M sticking with 707 great drainage it's all around good.