This is great, I was going to ask pretty much the very question the op started with.
If I may step in rather than starting essentially the same thread.
My variation with the op is that I have a mature heavily planted (60x22x15)tank. 70watts of plant focused light, a tec 1200 and a powerhead, the powerhead is due to the length of the tank and keeping flow through the planting.
Ph of between 6 and 7 and 0Am, 0Ni and 40 as far as I can see with nitrate, its in the tap water, with ferts dosed twice a week, no co2.
The tank seems to be near self sustaining. (I actually went and tested some water I dosed with Am to check my test kit), as stock is a mature RTBS (6yrs old) an older BN plec (our first fish sniff) and 9 harlequin tetra and a snakeskin that seems quite happy living as a harlequin. Oh, and quite a few assasins, got to be high teens at a guess. Could easily be more. With all the plants the bioload hardly stresses the filter.
I fancy having some shrimp, we are planning on increasing the stock but shoaling fish only shoal when spooked for so adding to the harlequin stock is pointless unless I want to deliberately scare them and a rtbs is a nightmare to get tank mates for. I have always had a hankering for some shrimp though.
Would I have the right environment, I can lose the plec for days so I'm sure a shrimp can hide.