Fish Cave LLC

Tucked inside an unassuming mini plaza in Appleton, Wisconsin — the kind of spot you'd walk right past if you didn't know what was inside — Fish Cave LLC is a hobbyist's store run by a hobbyist. The owner's dedication shows in a detail that experienced fishkeepers will immediately appreciate: every tank in the shop runs on an individual filtration system rather than a shared sump, meaning disease and parasites can't hop from one stock tank to the next. It's a labor-intensive choice that speaks volumes about the priority placed on livestock health.

The freshwater selection punches well above what you'd expect from the store's compact footprint. Guppies are a particular standout — the owner has imported strains never before available in the US, and multiple reviewers single them out as the finest in the state. German Blue Rams, peacock gudgeons, bettas with vivid coloring, and a rotating cast of exotic and rare species fill the rows of clean tanks.

Hardscape materials like stone and driftwood line the shelves for anyone planning an aquascape, and you can pick up blackworms, fish food, and general supplies without needing to order online. Customers regularly drive from Green Bay and beyond to browse the stock, and Fish Cave also ships — one reviewer ordered guppies and had them shipped the next day. The store supports the Milwaukee Aquarium Society, reinforcing its roots in the broader Wisconsin fishkeeping community.

The space is admittedly snug, and parking in the winter can be tricky given the oddly shaped lot, but most visitors find the density of the selection a feature rather than a flaw. If you have a specific species in mind, the owner is happy to source it. Staff — often the owner's family — are consistently described as patient and genuinely eager to talk fish, whether you're setting up a micro tank or hunting for something nobody else in Appleton carries.

It's a family operation built on passion, and repeat visitors keep coming back because the fish arrive home healthy and stay that way.