Jump to content

Kessil A500X Hands-On and Teardown

Recommended Posts


The Kessil A500X is the latest reef aquarium light from the company that has come to define high performance in multichip spotlight form factors. The power density of the 185 watt A500X is a new level of lighting concentration for light emitting diodes creating an intense point source which is the most comparable to metal halide lights. 

185 watts of power takes a lot of cooling but Kessil has a lot of experience in managing the temperature of their still unrivaled Dense Matrix Array. From their earliest A150 spotlight to the newest A360X Kessil has tightly integrated all of the control, optics, and cooling into the smallest form factor that physics and technology can allow. 

One key aspect that veteran Kessil users will really appreciate is how similar the A500X is to previous lights, using the same dials for manually adjusting intensity and the Tuna Blue spectrum, as well as the two USB type C connections for control using the wifi dongle, spectral controller, and daisy chaining additional lights. The attachment for the A500X is  is also identical to previous models which can either be suspended from the central mounting screw or can be affixed using the classic bracket. 


The brand new A500X might be approximately twice the size of the A360X but since that light is so small to begin with, the Kessil A500X ends up being a very reasonable size for how much power it puts out. The housing of the Kessil is only a little over five inches in diameter and under four inches thick, or 13.3cm across and 9.4cm in depth and it weighs in at less than a kilogram or 1.72 pounds.

We normally wouldn’t give much consideration to the weight of a light fixture but since the Kessil A500X is so small and powerful its mass has a great bearing on how it can be flexibly mounted over the aquarium with the preferred articulating gooseneck arm. Kessil’s existing gooseneck mounting arm can hold the A500X in place just fine but once you add the ball joint, wifi module and your choice of reflector the weight starts approaching the limit of what the gooseneck can handle. Although the solid mounting arm can handle the extra weight just fine, since this light is so bright most users will want to use it on larger tanks which would necessitate a taller mounting option, and/or a longer mounting arm extension to really make the most of where the light is directed. 


What makes the Kessil A500X so incredibly bright and efficient is that it packs in one hundred LEDs in a lighting package that is the same size as the A360X but are driven at only 1.8 watts each. The luminous efficiency of driving more LEDs at less power creates a balance of power & light output that is becoming the hallmark of the most sophisticated and efficient aquarium lights that very few manufacturers have achieved. 

The most practical way to get this balance of power and efficiency without overheating is to use many LEDs spread over a large area and accompanying heat sink to wick away as much heat as possible. In Kessil’s case the engineering is made even more challenging because they are generating a lot of heat in a tiny area and thus need to use a heatsink designed specifically for this ‘axial cooling’ application. 


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...