New tank setup

[Aquattro]

A new tank with new sand can/will look like a milkshake for a few days to a week. Normal.
Finding things other than sand in CAribsea...not normal. I haven't used a lot of bags, but I've personally never heard of this before. Removing the zinc and wood would be a good idea.
Do you have a skimmer running? That will help with the milkshake effect.