Hi,
Anyone know where to get plastic nuts for a Tunze Top off unit.
I'm not familiar with the product so I can't visualize the nut you're looking for but, Home Depot (and others like Ottawa Fasteners) stock quite a variety of plastic and nylon fasteners. Nuts, bolts etc, in all kinds of sizes. If it's a normal hex type nut or something similar they would probably have it. They're usually in the fastener aisle in little bins or compartments.