Octo NK250 Neck Extension
SKU: OCT-NK250
• Adds 3 inches of vertical height to your skimmer neck
• Significantly increases bubble dwell time for more efficient dissolved organic removal
• Precision-machined high-quality acrylic ensures a seamless, leak-free fit with the skimmer body
• Stackable design allows for aggressive tuning of internal water levels and foam dry-out
• Ideal For: Regal 250; SRO-5000; XP-5000; Diablo XS250/DCS-250
Reef Octopus
Globally trusted for premium protein skimmers and pumps, engineered in-house for unmatched reef filtration performance.
Reef Octopus NK-250 Neck Extension
The Reef Octopus NK-250 Neck Extension is a substantial performance modification designed to increase the filtration capacity of your 250-series or 5000-series protein skimmer by adding 3 inches of neck height. This extra vertical space is vital for increasing "dwell time"—the duration air bubbles remain in contact with dissolved organics—resulting in a more stable foam head and a higher concentration of waste in the collection cup.
Crafted from premium cast acrylic, the NK-250 provides the structural integrity and clarity required for high-end reef filtration. It is particularly effective for hobbyists with heavily stocked systems who want to push their existing Regal, SRO, or XP skimmers to handle higher bioloads without purchasing a larger footprint unit. The extension is stackable, giving you the modular freedom to adjust your skimmer's performance based on your specific sump depth and nutrient export goals.
Key Features
• Substantial Height Increase: Adds 3 inches to the neck to facilitate a taller, drier foam column.
• Enhanced Dwell Time: Longer bubble-to-waste contact leads to more efficient protein removal.
• Precision Fit: Specifically engineered for the diameter and sealing requirements of Reef Octopus 250/5000 bodies.
• Premium Build: Manufactured from high-grade acrylic to match the quality of Regal and SRO series skimmers.
• Customizable Performance: Stackable design allows for precise control over foam production.
Ideal For
• Regal 250 Owners: Fits Regal 250-INT, 250-SSS, and 250-EXT models.
• SRO-5000 Series: Compatible with SRO-5000int, 5000ext, and 5000sss skimmers.
• XP-5000 Users: Directly compatible with XP-5000int and XP-5000ext protein skimmers.
• Diablo and Specialty Units: Fits Diablo XS250, Diablo DCS-250, and DDNWB-250 models.
What's Included:
• NK-250 3-Inch Neck Extension
• Sealing O-ring]
Specifications:
• Height: 3 inches
• Material: High-quality Cast Acrylic
• Model Compatibility: Regal 250(int/sss/ext), SRO-5000(int/ext/sss), DDNWB250, XP5000(int/ext), Diablo XS250, Diablo DCS-250(int/ext)
• Warranty: 1-Year Limited Warranty
Warranty
CoralVue, Inc. hereby guarantees this product to be free from defects in material and workmanship for a period of:
- 1 Year
Warranty is activated on the date of purchase.
This Standard Limited Warranty applies and is limited as follows:
- To the product only as long as it remains in the possession of the original purchaser.
- To the product that has not been subject to accident, misuse or abuse.
- To the product that has not been modified, altered, defaced, or had repairs made or attempted by other than CoralVue, Inc.
- That CoralVue be immediately notified in writing within ten (10) days of first knowledge of defect by owner or his agent.
- That CoralVue, Inc. shall be given first opportunity to make any repairs, replacements or corrections to the defective construction within a reasonable period of time.
- Under no circumstances shall CoralVue and/or the Manufacturer be liable by virtue of this warranty or otherwise for damage to any person or property whatsoever for any special, indirect, secondary or consequential damages of any nature however arising out of the use or inability to use because of the product defect.
- Turn off the skimmer pump and remove the collection cup.
- Ensure the O-ring on the extension is clean and properly seated in the groove.
- Align the NK-250 extension with the top of the skimmer body and press down firmly to create a seal.
- Place the collection cup on top of the extension.
- Restart the skimmer and monitor the water level; you may need to open the gate valve to compensate for the added height.
Pro Tips:
Verify your vertical clearance.
Because this is a 3-inch extension, it significantly changes the overall height of your large-format skimmer. Ensure you have at least 4 inches of clearance above the new total height to comfortably remove the collection cup for maintenance.
Lubricate O-rings for a better seal. Applying a small amount of aquarium-safe silicone lubricant to the O-ring will prevent the acrylic from sticking and ensure a leak-proof connection, making it easier to disassemble for deep cleaning later.
Ideal for heavy bioloads. If you have recently added more fish or large colony corals, this extension is the best way to increase your skimmer's "reach" without replacing the entire unit. It allows for a more aggressive dry-foam setting that captures more organics per hour.