Thanks folks, most obliged.
WaterLife - I actually chose the pygmys for their delicacy around fry, as well as their general regional suitability. They seem to get along with the otos fine, and do draw them out of hiding a bit:
Thanks tons for the links too, but alas I've read them all (plus many more). Though it's not rare to find reports, it's very rare to find setups that people can repeat (I've been trying for over a year). It's also very rare to find people who take "fresh" or virgin otos and intentionally get them to spawn. Most spawning reports are incidental, where people get an initial spawn by fluke and keep them going.
I've never heard of fry surviving at pH>7.5, and the Amazonas report was included. He used fish he collected from the wild, and just simulated a grow out per the local conditions. Started with almost RO water, fed heavily for a bunch of months until conductivity was well over 1000, then triggered a spawn with cool clean water.
I've also been in touch with a researcher that's breeding 0.vittatus at the UofF, and he says those spawn more readily at ~81F. There's little understanding of the identification of various species, let alone their habits, so it doesn't surprise me that it's a dog's breakfast of info out there too.
I going to be setting back up some dedicated "simple" tanks that I'm using for breeding too, but this one is in the family room so I prefer it to look nicer. Don't care about a bit of algae here or there, just want to be able to dial more or less the correct fert regime in.
theatermusic87- good thought, but there's a bit too much ice out here right now. I'd also be scared of bringing something in that would devastate a colony (dragonfly larvae etc), and even if successful, it might not be readily repeatable. Worse than no results would be results I couldn't duplicate
Think I'll just stick with the plan for now, unless anyone can point out a flaw. I'll monitor nitrates and phosphates for macro dosing, and keep an eye on plant growth. I'll set something equiv up for micros (1ml PPS micro solution per 1 ml PPS macro sol'n), and start testing iron to see if there's a correlation.