I'm looking at introducing some colourful shrimp in my planted mixed tetra aquarium in the next month or so, and would like a good handful of mossballs for them.

I can't find info on the zebra mussels being an issue in the UK like it seems to be in the US and Canada.

Are our moss balls safer or not?

Also, would I actually need moss balls considering one of my two large bogwood pieces has one side (deliberately) covered in moss already?