This is an OpenScad script i made using Copilot for a skimmer for pipes. It's useful for ponds and aquariums where you have a pipe as overflow.
The STL is made for 50mm pipe but using the script, all parameters can be adjusted.

If you wish to adjust how far into the bottom the slots extends, change this part in the script "wall_thickness*6":

// Slots around the bowl
module slots() {
for (i = [0 : 360/slot_count : 359]) {
rotate([0,0,i])
translate([bowl_diameter/2 - wall_thickness*6, -slot_width/2, 0])
cube([40, slot_width, slot_height], center=false);
}
}