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Trigger Systems

Crystal Sump 18 (18" x 18") - Trigger Systems

Crystal Sump 18 (18" x 18") - Trigger Systems
Crystal Sump 18 (18" x 18") - Trigger Systems
Crystal Sump 18 (18" x 18") - Trigger Systems
Crystal Sump 18 (18" x 18") - Trigger Systems
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Trigger Systems specializes in aquarium sump manufacturing and are based here in the USA (Dallas, TX). All Trigger sumps come with a full top support brace which is made of a solid piece of material to prevent bowing over time from the humidity and water pressure. They also round the corners instead of squaring them which exponentially increases the strength of the corners.

The CRYSTAL series sumps are reasonably priced and have the same design and quality as Trigger Systems' RUBY series sumps but with all clear material. The CRYS18C can be used as a berlin style sump or a refugium style sump. Some features of the CRYS18C sump are:

  • Locking filter sock holder
  • Solid top support brace to prevent bowing
  • Foam filter block
  • Protein skimmer section
  • Refugium section

Section Details & Water Flow Path

The CRYS18C has 3 main sections. Section 1 of the CUBE design is where the water from the main tank enters through the filter sock. This is the section where the protein skimmer typically sits. Water flows from this section through a slit in the baffle into Section 2.

Section 2 is typically used as the refugium section. Having the refugium facing the front is a nice feature allowing easy maintenance and visibility of the refugium. Water flows to the right and then towards the back over the baffle through the overflow teeth. The wall with the overflow teeth moves up and down to set the water level for Section 1 and Section 2. The water then goes through a foam block and under a baffle into Section 3.

Section 3 is the return section where the return pump will sit, pumping water back to the display tank.

Draw String Tabs
Tabs are located on the top support brace in front of the 1” bulkhead fittings which are included. The purpose of these tabs is to provide a location for tying off 7” diameter filter socks that have draw strings.

Locking Filter Sock Holder
Filter socks snap and lock into the filter sock holders to secure the filter sock from falling out when it becomes clogged and needs to be cleaned or replaced. The 4” filter socks are 100 micron rating.


  • Dimensions: 18″ long x 18″ wide x 15″ high
  • Drain/Skimmer Section: 10.875″ x 11″
  • Front/Refugium Section: 17.5″ x 6.5″
  • Return Pump Section: 6.4375″ x 11″
  • Total Water Volume: 20 gallons
  • Skimmer Water Level: 9.5″ fixed
  • Drain Input Fitting: 1″ (x1)
  • Filter Sock: 4″ (x1)

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