Full-flow pool vaccum attachment

I created this thing to quickly suck large volumes of debris such as leaves, dead frogs, millipedes, and so on from the bottom of our pool. It fits into a standard pole and a standard pool vacuum hose attaches to it. The spherical end avoids damage to our vinyl pool liner.
I used a spring clip from a commercial brush head as I wasn't able to print anything that would maintain necessary tension. Thing 19216 (http://www.thingiverse.com/thing:19216) may be of use here.
I've been using it for