Spotted Catfish in a Koi Pond: Predator Risk, Not Cleaner Crew

Arizona pond (125 gal) with koi. Offered spotted catfish (likely Pimelodus or Synodontis) to "clean the bottom." Good idea?

No. Catfish Are Predators.

• Diet: Invertebrates, small fish, fish eggs, carrion. They hunt at night.
• Growth: Many species hit 6–12". A 125-gal pond is already cramped for koi.
• Behavior: Nocturnal, territorial, spiny fins (injure koi/goldfish).
• "Cleaning" Myth: They stir up detritus, making water dirtier. They don't eat algae or waste meaningfully.

Real Bottom Maintenance

1. Bottom Drain + Settlement: Gravity removes solids continuously.
2. Pond Vacuum: Manual suction (Oase, Matala) for periodic deep cleaning.
3. Proper Flow: Direct returns to sweep debris toward drain/skimmer.
4. Beneficial Bacteria: Regular dosing breaks down organics in situ.

If You Want a Bottom Dweller

Japanese Trapdoor Snails or Rosy Red Minnows (if no koi fry). But in 125 gal with koi? No room. Upgrade the pond or reduce stock.