Circular Drop-In Liner

Custom-fabricated box-welded pond liner built to your exact dimensions. Professional-grade materials, precision-welded construction, and a perfect fit for circular ponds, tanks, and water features.

Get a Perfect Fit with a Custom Box-Welded Liner

Stop fighting with flat liner material. Our circular drop-in liners are custom-fabricated to your exact specifications. Each liner arrives ready to drop into your pond, tank, or water feature with factory-welded construction. No folding, no bunching, no guesswork.

Why Choose a Box-Welded Liner?

Unlike flat sheet liners that require folding and bunching, box-welded liners are heat-welded into a true three-dimensional shape. This means cleaner installations, fewer wrinkles, and a more professional finished appearance.

Material Options

PP-45 (45mil Reinforced Polypropylene)

Our standard option for most pond installations. PP-45 features a woven polyester scrim core sandwiched between engineered coatings, creating a durable 45-mil liner. This material is stiffer and holds its shape well during installation. Fish-safe and backed by a 20-year exposed UV warranty. Available for ponds with a diameter of 96 inches (8 feet) or greater.

• Thickness: 45 mil
• Puncture Resistance: 120 lbf min.
• 20-Year Exposed UV Warranty
• Low Temperature Rating: -50°F

XR-3 PW (30mil Reinforced Premium)

Our premium option featuring an EIA (Ethylene Interpolymer Alloy) coating with woven nylon reinforcement. XR-3 PW is thinner and more flexible than PP-45, making it easier to handle and conform to your excavation. Despite being 30 mil, the advanced construction delivers more than double the puncture resistance of PP-45. Available for ponds with a diameter of 60 inches (5 feet) or greater. Suitable for potable water applications, aquaponics, and hydroponics.

• Thickness: 30 mil
• Puncture Resistance: 275 lbf min.
• 20-Year Warranty (when covered by soil or water)
• Low Temperature Rating: -30°F

Which Material Should I Choose?

For circular ponds with a diameter of 8 feet or larger, PP-45 offers excellent durability at a lower price point. If your pond diameter is between 5 and 8 feet, XR-3 PW is required due to fabrication constraints. XR-3 PW is also the better choice if you prefer a more flexible liner that's easier to position during installation, or if puncture resistance is a priority.

Optional Add-On

8oz Geotextile Underlayment – A protective fabric layer installed beneath your liner. Helps prevent punctures from rocks, roots, and rough surfaces. Sold by the square foot to match your liner dimensions.

How It Works

Use the configurator above to enter your pond's interior dimensions (diameter and depth) along with your desired flange size. The flange is the flat lip that extends outward from the top rim of the liner. It gets sandwiched between your pond wall and the surrounding edge treatment (stone, decking, gravel border, etc.) to anchor the liner in place. We calculate the exact material needed and show you the price instantly. Your liner is fabricated to order and typically ships within 5–6 business days.

Before You Order

Measure twice, order once. These liners are custom-fabricated to your exact specifications, which means they are non-returnable. We can't restock or resell a liner cut to your dimensions. Take the time to measure your pond carefully. If you're not sure, contact us before placing the order and we'll help confirm the right dimensions.

Flexible, not rigid. This is a drop-in liner, not a free-standing structure. It requires a properly excavated hole or a supportive frame to maintain its shape.

Minimum pond size. Most custom box-welded liners are fabricated for ponds of approximately 200 gallons or larger. Smaller projects may be outside our standard fabrication range. If the configurator shows "Contact Us to Order" for your dimensions, please reach out and we'll help determine the best path forward.