Equipment diy ATS

Interesting following this thread, just wondered why everyone seems to gravitate to the "slot cut into pipe variety", what's wrong with having the water coming out of the pipe, and dangling the mesh a few millimeters underneath it?
Slirp87, I see that you eventually employed two versions of light shielding to avoid the slot from filling with algae, which was the better?
With regard to the original design, couldn't the clear drip pipe be painted with something inert like black enamel paint to stop algae forming inside? I liked the spouts on it (this harks back to my question of having the screen hang underneath)