First Large Pond (4,500 Gal): Biofilters, UV, Aeration, Turtles, and pH Testing

Situation

First pond: 4,500 gal, two waterfalls, three pumps with homemade biofilters. Wants to buy a biofilter with UV, asks about aeration for koi, turtles, and pool pH test kit.

Biofilter + UV

• If homemade filters work, why buy? UV clears green water but not needed with good plant balance.
• No specific brand recommended; many options exist.

Aeration

• Waterfalls provide aeration; add more in summer if warm/overstocked.
• Oxygen demand: orfe > koi > goldfish > native fish.

Turtles

• Will nip large fish, eat small fish/plants. Many keep them anyway.
• See turtle pond guide.

pH Test Kit

Pool kit works but target range differs (ponds: 7–8). Better to use a pond‑specific kit.

Helpful Pages

• UV guide
• Koi care
• Water chemistry