Our Belgian national team has a few architects who played around with the idea of the ideal pool.
The concept is a fully transparent, transportable pool with 800 seats around it, audio-visual installations, drinking stands, in a large bubble.
The floor is made out of a special type of plastic, optimal for playing hockey. The field is lid from below, so spectators can see the entire field when it's dark in the dome. When a fault is commited and the ref pushes the button, the color of the field turns red and a signal is given.
I don't have visuals on this computer, but Romain can set it up. Certain of you might have seen the plans in Sheffield.

Worst part is, that this is completely feasable. The investment would be 2 million euros. The filtration system would be done by the Belgian company providing the filtration of Cirque du Soleils underwater Vegas show. This would make the water 100% filtered with great view at every time.
2 million is not that much money for a new pool, but most cities here are currently not really keen on investing into it, yet.

I'll try to post some visuals here asap.