Internal Overflow Strainer

I use a 1/2" PVC elbow on the inside of my overflow bulkheads. My shrimp think it's a water slide and I usually find them in the sump later.

I started off with a cap style, but if it became clogged, I'd have a spill. So I came up with these, that still provide straining, but if the water gets high enough it will still drain unimpeded.

This style goes inside of a female 1/2" PVC fitting.

**Updated 2019-03-29: Added a version where the gaps are smaller to attempt to get small fry from s