The V3 Shadow® Overflow is the latest version of the SHADOW® overflow system. With over 5 Years of feedback from our customers and 10 years since we invented this style of overflow, we have made some major advancements in our Shadow Overflow Technology! Here are some of the new features:

What is the Shadow® Overflow?

The Shadow® Overflow is a device that is used to divert water flow from your aquarium into your filtration sump. This overflow can be used on any Freshwater, Marine or Reptilians habitat.  There are no limitations on where you can use this overflow system.

360° view of the overflow system


Full Screen Version located Here: HD Full Screen 360º View

Previous owners, please read read the Q&A for the V3 Shadow® Overflow, if you are wanting upgrade information. All of our Shadow V1 to V3 overflows are compatible and upgradeable.

Features of the V3 Shadow® Overflow

  • Sealed Rear Lid and Rear Box Design – Rear Lid and Rear Box flange makes a watertight seal. This helps completely reduce salt creep formation on the exterior box.  The V3 Rear lid and Rear box is virtually watertight and prevents any water from exiting the box. No other overflow on the market has this capability.
  • 1.5″ Exterior Box Slip Fitting Openings – The 3 x 1.5″ Slip fitting openings in the rear box to allow for better fitting of ANY 1.5″ PVC Pipe or Fitting. This gives you maximum flow with a very small external box footprint. The smallest external box to flow rate ratio available. No big clunky exterior box behind your tank. Just small, sleek and compact.
  • Re-Engineered Polymer Construction – The Rear Box Material has been changed to a proprietary new polymer blend! This new polymer allows you to use ANY type of PVC or ABS glue or primer you choose.  This means that you can use any PVC Cement that you can find locally or have on hand already. It also makes the rear box even more durable than before!
  • Quiet Flow™ Weir design – The Shadow V3 now has a redesigned weir that makes it the quietest front weir box available. We have re-engineered the front internal box and designed an integrated Quiet Flow™ system. This allows for the same high surface skimming capability with no noise from internal flow pumps or wave makers.
  • Upgradeable! – Our Current Shadow V1 or V2 customers can easily upgrade their overflows to the V3. V2 Customers can easily upgrade without any replumbing of your system. And The V3 will be upgradeable with any future advancements.

100% Injection Molded for the highest quality and most precise fitment! Easy to install and very low profile. Check out the specs of this overflow system. It can be used with as little as 400 gph all the way up to 2500 gph. Tanks from 10 Gallons all the way up to 400 Gallons in size. If you need more flow, just add a second box.

Featuring a removable weir for ease of maintenance and our molded design for fail-safe operation. Our ultra slim design has revolutionized the aquarium overflow and how aquariums get water into their filtration systems. It is a very simple to install, plug and play overflow system. Quiet operation when used to our specifications and tuned properly to your system. Our years of testing and development are what sets our overflow system apart from anything else available.

Designing the overflow –

Being reef hobbyists ourselves, we spent years working on the design of this overflow. We were tired of the same old overflow that took up a quarter of the tanks real-estate and sounded like a toilet flushing. We tested hundreds of variations and options before we came to this design. Our fundamental goal was to create a low profile and quiet internal overflow box, while maintaining the higher flow rates desired by reef hobbyist. We wanted an overflow system that everyone would want to use. Originally, we designed the overflow to fulfill a need for a high flow, quiet, plug and play operation. We built them by hand with flat sheets of acrylic. Using flat sheets for an intricate design like we envisioned was not possible and had limitations. Designing the overflow with 3D software allows us to add features not possible when building it by hand out of flat acrylic. As we moved forward with the design, we wanted to make a product that could be produced for everyone to enjoy. Injection molding was the answer. While it took us a long time to design and manufacture this overflow, it now is exactly where we wanted it to be.   This overflow system was designed by Synergy Reef Systems in the USA!

Manufacturing the overflow –

Injection molding allows us to make every part exactly the same. Every part is molded with the same tolerance and specification. Unlike other hand build models, molding allows the Shadow to be precise in fit and form. We use the highest quality Polycarbonate and ABS in our molding process. Our quality is second to none! There are lots of imitation overflows out there, but ours is the highest quality available, period!

This is a self-install kit. You can drill the tank and install this yourself! Instructions are located here: 16″ Shadow® Overflow Installation Manual

Drilling template is included with the overflow and we recommend you use the template when the overflow arrives to align it perfectly. But if you need the drilling template .pdf it is located here: 16″ Shadow Overflow Drilling Template






SKU 1147
Barcode # 019962178108
Brand Synergy Reef
Shipping Weight 3.5000kg
Shipping Width 0.240m
Shipping Height 0.160m
Shipping Length 0.470m

Others Also Bought

More From This Category