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D-D Slimline OTM Rail System

The D-D over tank mounting system offers a flexible solution for mounting single or multiple Aquaillumination Hydra HD lights on a fixed rail above the aquarium. The OTM rail is a rigid, anodised aluminium profile, available in four different lengths, and includes clips for power cable management. The rail can be suspended from the ceiling using the AIWIRE05 wire kit or mounted directly on to the aquarium with a set of OTM Slimline Brackets.

Each light is attached to the rail using a swivel arm that can be positioned anywhere along the length and will also allow the light to be rotated 360 degrees.


  • Strong aluminium rail profile
  • Available in 4 different lengths to suit 90,120,150 and 180cm aquariums
  • Rail can be easily cut down for non standard size aquariums
  • Black anodised rail finish
  • Tank mount brackets or suspension wire kits available
  • Swivel arm attachments to allow lights to be rotated 360 degrees
  • Fully modular concept
  • Rail includes cable management clips
  • Infinitely adjustable hanging positions along the length of the rail
  • Suitable for the latest version HYDRA 64, HYDRA 32 and HYDRA 26 LED Lights

Swivel Arm Light Mounts

Each OTM rail kit comes complete with swivel arms and fixings for attaching HYDRA 64, HYDRA 32 and HYDRA 26 LED Lights. These can be fixed into any position throughout the length of the rail by simply sliding it along and then tightening the fixing screw. With a single pivot point in the middle each arm they can be rotated throughout 360 degrees allowing the light to be mounted facing left to right, front to back or anywhere in-between.


OTM Rail 3, for 90cm aquarium includes 2 x swivel arms

OTM Rail 4, for 120cm aquarium includes 2 x swivel arms

OTM Rail 5, for 150cm aquarium includes 4 x swivel arms

OTM Rail 6, for 180cm aquarium includes 4 x swivel arms


Additional swivel arms can be purchased separately to increase the number of light units on the rail and can be easily added at any time.

Direct Aquarium Mounting

Optional slimline lightweight OTM brackets are available to mount the OTM rail directly onto the rim of an aquarium. These are produced from a sturdy 4mm thick aluminium piece that is powder coated using a hardwearing black corrosion resistant finish to match in with the rest of the OTM system. The brackets have a slim profile to reduce their appearance and make them as unobtrusive as possible when the aquarium is viewed from the front.

Each bracket is securely held in place using two glass reinforced plastic feet that allow them to be positioned anywhere across the width of a rimless aquarium with glass up to 22mm thick.

Suspended Mounting

The AI WIRE 05 hanging wire kit is suitable for suspending the D-D OTM Rail system and is available separately. When using on the OTM rail system the Y connector in the wire set can slide into any position along the length of the rail to offer maximum flexibility and allow them to be lined up with a suitable fixing point above. The Y connector can also be easily adjusted to tilt the rail set backwards slightly to limit glare or light spill over the front of the aquarium. Built in slide adjusters also allow the wire kit to easily move the rail up or down to either set a suitable running height or to move the lights up out of the way for easier access into the aquarium.