Summary

I made this to fit perfectly over this specific sponge filter I got on Amazon:
https://www.amazon.com/dp/B078HDL21V?psc=1&ref=ppx_yo2ov_dt_b_product_details

I personally printed it at 0.14mm layer height and 100% infill just to make sure it wouldn't float, but you could probably get away with less infill.