I can see getting back to the basics and going low-tech, but why no skimmer? The principles are very low-tech (adhesion on bubbles, right) and you aren't putting additives into the system.
A skimmer will help you reduce the maintenance on your tank, which is I think what you are looking for.
If you select your corals and fish right, and stock low, you could have a successful low maintenance system.
What made you go anti-tech? Just curiosity?
I have a 55 sorta reef with a lot of live rock, several species of macro in the display, and some hardy corals (Turbinaria, gorgonian, lots of cabbage leathers, Porites, zoanthids and mushrooms).
Set-up:
shallow sand bed
~75 lbs live rock
Rena smartfilter (running empty, for circulation)
CPR BakPak skimmer
CPR Aquafuge refugium (with chaeto, lit 24/7)
1 powerhead
4 x 65-watt PCs (I'd go with T5s if doing it again)
The tank is stable and established. It's pretty heavily stocked, so it IS fed every day, and it's a struggle to stay ahead of nuisance algae. With a lighter load of fish, I think this tank might approximate what you are looking for.
I have:
green wolf eel blenny - about 4 years
2 seahorses - had 3 years and 1 year
reticulate boxfish - less than a year
marine betta - less than a year
I do water changes about every 2-3 weeks, usually 5 gallons at a time. I clean out the skimmer collection cup as needed, usually just once or twice a week. Top off as necessary, every few days to once a week. I feed twice daily, seahorses need it and the other fish appreciate it. But less fish bioload would result in less frequent feeding.
plenty of people do fine with tap water for their tanks, just depends on the quality of your local water. have you checked your municipal water test?
