So I went ahead and built a more simple version of what I imagined haha. I drilled a hole in the cap slightly smaller than the hose and jammed it in and then temporarily duct taped it to do a test. I'll silicone it later or find something that will be waterproof and flexible. Also drilled four tiny holes for maximum sprayage! ha
I was surprised at the amount of current, it seems perfect for my 10 gallon. Of course when I add media (rocks, sponge bits, ceramic, w/e) it will slow the flow down a little but so far I'm pleased with it! Now just have to soak the sticker off so it's all clear and waterproof the bottle cap and bingo!
very simple design ha, so that means less can go wrong :P
OH and if anyone has any ideas for how to "pivot" this thing on top of back rim I would appreciate input! I am scratching my head trying to figure out a way that will look minimal and not crappy and on the cheap side (of course.)