The Fluval Flex 123 liter/32.5 gallon aquarium comes with a very weak light fixture. The lid can accommodate a second identical light but you need to use their bracket, and you'll end up with two very weak light fixtures.

The light also costs $100 and is bluetooth-only.

This bracket design allows you to comfortably fit up to 153mm (6in) of light fixtures, either a single monster light or multiple smaller ones. With it I can mount the original light fixture (41mm) plus a much more powerful fixture I bought from Amazon (81mm) for a total of 122mm (4.8in) and leave a gap between each fixture so they're not touching.

You use zip-ties to hold the light fixture in place. Yes, zip-ties. I know we're all about printing everything from scratch and I should have design a part that clicks together with the base, but it would have to be thick enough to safely support the weight of a light fixture which would make it large enough to always be dipping itself in your tank's water. A good zip-tie is going to be incredibly durable, much stronger than what you're (probably) going to print, and is super-tiny.

The slots along the sides are where you insert your zip-ties into. They're spaced 12.34mm apart and have dimensions of 5mm x 1.5mm. With this design you can fit any size and shape light fixture you want onto your aquarium's lid.

Printing Instructions

You should print this item as-is! Do not print it flat! If you print it flat your layer orientation will be weaker vs if you print it on its side. This bracket will hold your electric light fixture an inch or less from your aquarium and your expensive fish! Do not skimp on print time by trying to print flat. Take the extra time to print this as-is (on its side!) to increase the item's strength.

For more information please see https://markforged.com/learn/3d-printing-settings-impacting-part-strength/

You will want to use a brim or raft since the surface area is so slim.

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