I believe that they're safe for shrimp.
I don't believe that you should be paying $15 for $3 worth of Lowes or Home Depot PVC fittings. This filter simply operates off of the principals of a DIY sponge filter. It's just that he moved where the filter material occurs in the flow.
Just a DIYers' $.02. It is of course your money and it is a slick looking filter.
They asked me to move because I was blocking a fire exit.
If you're flammable and have legs, you are never blocking a fire exit. -Mitch Hedberg