Wide 40-Inch Waterfall
The detachable weir creates a substantial entry point for a broad waterfall or stream while allowing the pond liner to be sealed directly to the box.
Extra Large 40" Elite Waterfall Box
$1,199.99
Proudly made in the USA.
- Waterfall width: 40" spillway
- Dimensions: 35.75" × 50" × 30.75"
- Maximum recommended pump flow: 20,000 GPH
- Maximum pond volume: 10,000 gallons
- Inlet size: Two 3" spinweld fittings
- Warranty: Limited lifetime warranty for the waterfall-filter box
Large-capacity biological waterfall filter
Extra Large 40" Elite Waterfall Box
Build a broad natural-looking waterfall while adding biological filtration to a large garden or fish pond. The PB1243 combines a 40-inch spillway, high-flow capacity, two 3-inch plumbing inlets, included Matala filter mats and a landscape lid in one contractor-grade waterfall-filter component.
Spillway: 40 inches
Maximum flow: 20,000 GPH
Pond volume: Up to 10,000 gal.
Connections: Two 3-inch spinwelds
Item number: PB1243
Built for Large Ponds and High-Flow Waterfalls
Biological Filtration Included
Two green Matala mats provide durable mechanical and biological filtration surfaces. The included mesh bag can hold your choice of additional biological media.
Flexible Plumbing Layout
Two factory-installed 3-inch spinweld fittings let you bring the feed line from either side. The second connection can support another pump line or a back-flush arrangement.
Before You Order
This is the waterfall box and filtration assembly—not a complete pond kit. Plan for a pump and skimmer sized to the pond and waterfall, 3-inch flexible PVC pipe, pond liner and underlayment, PVC primer and cement, rockwork and site preparation. Biological media for filling the included mesh bag is also sold separately.
Choose this model when: you need a 40-inch spillway, pond filtration for up to 10,000 gallons and a recommended pump flow no greater than 20,000 GPH. Confirm the full 35.75" × 50" × 30.75" box footprint, plus installation and plumbing space, before purchase.
What Comes with PB1243
Waterfall & Filtration Assembly
- Extra Large Elite waterfall-filter box
- Detachable 40-inch weir
- Landscape lid
- Two green Matala filter mats
- One 24" × 36" mesh media bag
Plumbing & Installation Parts
- Threaded male adapter and threaded plug
- Self-tapping stainless steel screws and screw caps
- Liner clips
- Black silicone and Teflon thread tape
- Installation instructions
Not Included
- Pump, skimmer and electrical service
- 3-inch flexible PVC pipe, PVC primer and cement
- Pond liner and protective underlayment
- Biological media for the mesh bag
- Waterfall foam, rockwork and landscaping materials
Useful System Components
- Bacti-Twist biological filter media—the installation guide recommends 10 cu. ft. for this model
- Pond pumps
- Mechanical skimmer boxes
- Pond liner and underlayment
Rockwork note: Rocks and gravel help finish and conceal a pond installation but are not included with this waterfall box.
Extra Large Elite Specifications
SKU:PB1243
UPC:897570001243
Spillway width:40 inches
Dimensions:35.75" × 50" × 30.75"
Maximum recommended flow:20,000 GPH
Maximum pond volume:10,000 gallons
Inlet size:Two 3-inch spinweld fittings
Recommended additional media:10 cu. ft. Bacti-Twist
Construction:Blue Thumb engineered plastic component
Country of manufacture:Made in the USA
Waterfall-box warranty:Limited lifetime warranty to the original purchaser
Product type:Biological pond waterfall filter
Compare Waterfall Box Sizes
The Extra Large Elite is the highest-flow model in the current comparison. Select by pond volume, planned waterfall width, plumbing size and the pump flow delivered after head-height and friction losses—not by spillway width alone.
| Specification | DIY 1200 | DIY 1500 | DIY 2000 | Small Elite | Medium Elite | Large Elite | Extra Large Elite |
|---|---|---|---|---|---|---|---|
| Spillway | 14" | 14" | 20" | 14" | 22" | 30" | 40" |
| Dimensions | 19" × 15.5" × 14.5" | 20.5" × 20" × 15.75" | 22" × 23" × 19" | 23" × 24.75" × 21.75" | 31" × 30.5" × 23" | 31.75" × 40.5" × 25.75" | 35.75" × 50" × 30.75" |
| Maximum flow | 2,000 GPH | 2,500 GPH | 4,500 GPH | 3,500 GPH | 6,000 GPH | 10,000 GPH | 20,000 GPH |
| Filters up to | 1,200 gal. | 1,500 gal. | 2,000 gal. | 1,500 gal. | 3,500 gal. | 6,000 gal. | 10,000 gal. |
DIY 1200
Spillway:14"
Dimensions:19" × 15.5" × 14.5"
Maximum flow:2,000 GPH
Filters up to:1,200 gal.
DIY 1500
Spillway:14"
Dimensions:20.5" × 20" × 15.75"
Maximum flow:2,500 GPH
Filters up to:1,500 gal.
DIY 2000
Spillway:20"
Dimensions:22" × 23" × 19"
Maximum flow:4,500 GPH
Filters up to:2,000 gal.
Small Elite
Spillway:14"
Dimensions:23" × 24.75" × 21.75"
Maximum flow:3,500 GPH
Filters up to:1,500 gal.
Medium Elite
Spillway:22"
Dimensions:31" × 30.5" × 23"
Maximum flow:6,000 GPH
Filters up to:3,500 gal.
Large Elite
Spillway:30"
Dimensions:31.75" × 40.5" × 25.75"
Maximum flow:10,000 GPH
Filters up to:6,000 gal.
Extra Large Elite — this model
Spillway:40"
Dimensions:35.75" × 50" × 30.75"
Maximum flow:20,000 GPH
Filters up to:10,000 gal.
Need a smaller biological waterfall filter? Compare the Large 30" Elite, Medium 22" Elite and Small 14" Elite.
Installation Overview
Read the complete installation guide before site work. This large box needs a compacted, stable base, space for two 3-inch connections and careful liner attachment so the spillway remains level and watertight.
Choose the Location
Place the waterfall opposite the skimmer for pond circulation, either at the pond edge or at the top of a stream.
Prepare the Plumbing
Select the feed side, apply thread tape to the included male adapter and plug, and plan the second fitting for a plug, second pump line or back flush.
Set and Level
Compact the support area. Keep the box level side to side and tilt it slightly forward—about one-quarter bubble—so water moves toward the spillway.
Connect 3-Inch Flex PVC
Clean the surfaces, use PVC primer and cement, seat the pipe fully and hold it while the joint sets according to the adhesive directions.
Attach Liner and Weir
Leave liner slack for rock weight, seal the box face with the included silicone, fasten the weir and trim only after the assembly is secure.
Add Media and Finish
Install the Matala mats, fill the media bag with separately purchased biological media, fit the lid and complete the rockwork without restricting service access.
Care and Seasonal Maintenance
Inspect flow and clean accumulated debris as operating conditions require. The official guide recommends a thorough waterfall-media cleaning about once per year, when pond water is coldest or below 50°F. Rinse media with collected pond water when possible; chlorinated tap water can harm the beneficial bacteria living on the media.
For climates with prolonged freezing, follow the pond and pump winter-care instructions for your complete system. Rinse and store removed media where appropriate, and restart with clean components in spring.
Product Resources
Pond Kit Installation Overview
This official Blue Thumb video explains the broader pond-kit installation sequence. It is not specific to PB1243, so use the model-specific Elite Waterfall Box guide above for the 40-inch box, 3-inch plumbing and exact assembly details.
“How to Install a Pond Kit: Step-by-Step Guide,” courtesy of Blue Thumb. Pump, skimmer, liner, plumbing, rockwork and landscaping shown in the video are not included with this standalone waterfall box unless separately listed above.
Questions About Sizing or Installation?
Our Sales/Tech Team can help you confirm waterfall width, pond volume, pump flow, plumbing size and site requirements before you order.
Frequently Asked Questions
Is PB1243 a complete pond kit?
No. It is a biological waterfall-filter assembly. A pump, skimmer, flexible PVC pipe, liner, underlayment, rockwork, electrical service and other site materials must be selected separately.
What pump flow can this waterfall box handle?
The maximum recommended flow is 20,000 GPH. Size the pump by the actual flow delivered after total head height and plumbing losses, and do not exceed the box’s recommended maximum.
What size pond can it filter?
Blue Thumb lists the Extra Large Elite for ponds up to 10,000 gallons. Fish load, feeding, debris, circulation and total filtration design also affect real-world water quality.
Is filter media included?
Two green Matala filter mats and one mesh media bag are included. Biological media used to fill the bag is not included; the installation guide recommends 10 cu. ft. of Bacti-Twist for PB1243.
Can the plumbing enter from either side?
Yes. The box has a 3-inch spinweld fitting on each side. Use either side for the main feed line; the other can be plugged or incorporated into a planned second-pump or back-flush configuration.
How should the box be positioned?
Set it on a compacted base, level it from side to side and tip it slightly forward—about one-quarter bubble—so water flows evenly toward the spillway. The guide recommends locating it opposite the skimmer for pond circulation.
How often should the filter media be cleaned?
Operating conditions vary, but the official guide recommends a thorough waterfall-media cleaning about once per year when pond water is coldest or below 50°F. Rinse with pond water when possible so chlorine does not damage the beneficial bacteria.
What warranty applies to the waterfall box?
Blue Thumb’s current plastics warranty provides limited lifetime coverage against manufacturing defects for Blue Thumb-branded engineered plastic waterfall filters purchased by the original purchaser. Proper installation is required; modifications can void coverage, and labor and freight are excluded. Review the warranty PDF for full terms.
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