The limiting factor will be filtration, not light.
While I can't help you with direct answer on your question, there are some considerations:
Usually available in LFS groups of non-photosynthetic corals are:
1. LPS: Sun corals and their more expensive relatives, dendrophyllia, rhiso, balanophyllia, cladopsammia. They come in different colors and shapes.
Have to be fed as any other LPS - small pieces of meaty food, whole organisms are preferable (mysis, plankton) - but at least twice a week. More frequent feeding is preferable.
Drawback: manual feeding, high (but rare, comparing to other groups) water pollution.
If you will take this route, use very small corals - few polyps - to preserve water quality, and avoid at beginning sun coral with very low polyps.
2. Gorgonians: Menella seems to be reliable, but I didn't try it.
Several times a day (or continuous) feeding by mouth-sized food, mainly zooplankton and substitutes. Moderate-high or high flow.
Uneaten or settled on the bottom food should be filtered out. Do not allow it rot under the rock.
3. Soft corals, inflating and deflating. Most arguable group. Continuous feeding (with corresponding filtration) and high flow. The trick will be keep food in water column around these corals for prolonged time (wavemaker, twister-like flow, add your version).
Skimmerless non-photosynthetic tanks: I tried for year or so, tank lived on massive water changes, this is tiresome after a while, and alkalinity of new water should be not 15 dKH :eek1:
What you can do with Emperor 400 to be able to filter the small particles: use in basket cartridges 50 micron Filter Pads ($10 18x24" or so, but requires daily change and twice a week washing). Or at the place of blue filter pads. Sorry, but this all I was able to achieve with it. More (and more frequently changed) carbon, phosphate remover, maybe even some denitrator and UV.
You will be able to remove some particulates, but dissolved organics still will be a problem.
Aiptasia may start to flourish on a good feeding, you will need means to control it.
Pores in LR may become covered by sediment of food on microorganisms, consuming this food too. Or saturated by phosphates. I'm not trying to scare you, just be aware of the situation.
Some people kept gorgonians in non-skimmed tanks, but I don't know outcome after 6-8 months.
This is not a coral, but it don't require light - tube anemone. I like them, but current inhabitants may conflict with it, and they require a place of peace and quiet. Main danger is to buy a big specimen, mine became twice or more larger in home tank, then it was in LFS.
Small pieces of meaty food, mysis, plankton, not even every day. No fuss, no muss.
HTH
