The popular Fluval Spec V aquarium can be easily adapted to a saltwater reef tank. However, the stock foam insert isn't exactly ideal for saltwater since you want to maximize water flow and you really don't need that much mechanical filtration.

The tank runs just fine without the foam insert entirely, but at the expense of particles floating around in the water column. To remove this while minimally disturbing the already compromised flow from the pump, I've come up with a basket that attaches to the sump grills and will hold polyester filter floss. This filter floss can be easily accessed for rinsing off periodically.

I printed this in PETg at 100% infill. You should avoid PLA if your tank's pH is higher than 7.8.

There are two versions, one is larger.