My hubby brushes in BQ builders soft sand .

We were recommended 'silver sand' as it is finer. We were also told not to seal it as it causes problems with rainwater (i.e. drainage)

Sme of the gaps are fairly big should i pack them with something before using the sand? I have pushed the blocks back as near together as i can

Only kiln dried sand should be used .As the name suggests the sand is dried to fall easily into the smallest of joints and the sand itself is graded to ensure the particles "lock" together to prevent movement of the blocks and thus unsightly gaps between the paving.

Cheers guys x

And technically, you should hire a whacker plate - monoblock usually is laid on sand, which has had the whacker plate machine used all over it, then the blocks are laid, kiln dried sand goes over the top, and you use the whacker plate all over the area to vibrate the sand down, adding sand as it disappears, till all the joints are full.