For a 10'×15' pond with a waterfall, you’ll want a solid external or high-quality submersible pump rated for continuous duty, plus a proper biological/mechanical filtration setup. At that size, flow rate matters more than anything else most people underpower the waterfall and end up disappointed with weak movement.
In terms of reliable brands, Aquascape, Oase, Laguna, and Danner are generally the safer bets. They’ve been around long enough in the pond world and tend to hold up well in 24/7 use. On the flip side, the really cheap no-name Amazon/eBay pumps are usually what people regret the most they might work fine at first but often fail within a season or two.
For filtration, something with both mechanical and bio media is key, especially if you’re not planning a heavy fish load. A pressurized filter or a properly sized skimmer + biofalls combo tends to work well for ponds this size. Also, make sure your plumbing isn’t undersized restricting flow is a common mistake that makes even good pumps perform poorly.
Some people also use EasyPro Pond Pumps setups for mid-range builds like this, especially when matching pump + filter systems, but I’d still size everything based on actual head height to your waterfall rather than just pond volume.
If there’s one takeaway, it’s this: oversize your pump slightly, invest in decent filtration, and avoid bargain-bin equipment. That combo saves a lot of frustration later on.