If someone starts a new list here's what I'd put on it based on my 75 gal tank that I originally had 3-T12 lights raised about 5 from top of tank .. which I now know after checking the lux/par on it was very, very low, low light. New lighting is good reflector T8x2 and 1-T12 with plant grow bulb with an ok reflector. The t12 is a bit lower than the t8 fixture and used mostly to simulate dawn/dusk. I calculated I'm low light maybe 20-25 par.
Here's the list of my plants that grew and/or survived with very, very low light probably less than 15 par LOL AND in coarse gravel. The better growth now is probably a combination of better light AND better substrate (STS):
-- grew some but not nearly fast as it does now with my good T8 lights
Water Sprite -(Ceratopteris thalictroides)
-- seems to grow in any light ...just wish it would get taller before breaking off plantlets
Wisteria -(Hygrophila difformis)
-- grew at moderate rate before .. now grows fairly fast with better light so that helps since I want mine as tall as the tank.
Dwarf water lily (Nymphaea stellata)
-- grew decent before now really taking off
Red Myrio (Myriophyllum heterophyllum)
-- not red in my tank but grew. It's more of a bronze color. Color hasn't changed with better light but it grows a bit faster and adds a color other than green.
Ludwigia, Broad Leaf (Ludwigia repens)
-- seemed to grow faster than the others because it was stretching to get to the light I realize now. Grows wider, longer leaves now rather than getting tall and spindly. Not real red but does add a touch of reddish color to the tank. Wish it would start growing up/tall.
- was ok .. grew some. Looks really nice at any height though.
All of the above would probably have appeared to grow better, faster in smaller tank but since I needed/wanted tall plants quickly having a large tank may have effected my judgement of growth rate. Especially when the plants start off 6"-10" and I want them to be 18".
All grew .. some a lot slower than others but makes them good low maintenance plants when using very low light.
When using coarse gravel the following didn't do well at all. I think it was the gravel more than the low light though. But even now with bit better light they're still just slow growing.
- just wouldn't grow, kept getting shorter because of the stem ends rotting off and unable to root in that gravel. Growing better now in new substrate .. not real fast but at least now it's rooting rather than rotting.
Corkscrew Val (Vallisneria americana var. biwaensis)
- same problem .. just wouldn't grow in the gravel. Doing better but still not a fast grower for me.