I toyed with the idea of toilet flapper surge tanks over my 75g some years ago. In the end I discontinued them because the flappers kept getting hung up (a problem with the way I implemented them, not a problem with the idea of a toilet flapper surge tank, per se), and also just because I was sort of disappointed with the amount of flow that came out. I had 2 1-1/2" outputs per tank and it was just as if someone had turned on a pump for 30 seconds. I really wanted a more dramatic "crash" of water but realized I had nowhere near the height to work with for the kind of head pressure that would take.
I started wondering how it would be if, instead of a toilet flapper, one could use an automated valve of some kind. Then you could have it open and close at intervals and probably reduce the amount of air introduced into the tank (unless, of course, the bubbles are something you want - after all most waves do sort of create transient bubbles).
I've also wondered what a Carlson surge tank would look like if you used really large diameter pipe so the tank emptied briskly..
Anyhow, fun stuff, wish I had more time/energy to play around more with this sort of thing.
Good luck with your experiment, can't wait to see it in action!
