I have played with surge devices and have built several varieties - and they all work - kinda - and they are a lot of fun to mess with.
I tend to sketch things out on paper - talk about them with my brother (broncofish) and then never take action (not as handy as I'd like to be).
Currently thinking of a very small surge device hooked to a SCWD - so I can use a lower powered powerhead and pump up a small resevoir - have it spill out to the scwd and get not only an alternaing current via the scwd but a variety of force of water based on the surging effect.
Also wondering about hooking a scwd up to a tatratec output on my nano ..... just an idea not sure if it would be worth the effort or not.
A couple of other ideas in the works as well - but nothing I am thinking of sharing as of yet ....
what about you??