Cool! 30 days and the echinodorus haven't dissolved...

I bought a few dozen assorted echinodorus a month ago at a local fish club
auction. All had been grown emersed, and appear to be a mix of E. bleheri
(sold as 'Black Amazon Sword,' which I think is usually bleheri) and something
sold as 'Amazon sword,' which I think is that common variety whose name
escapes me at present. As usual, buying stuff for tank space I didn't have,
I ended up potting the plants in clay pots and yogurt cups (bought more than
I had clay pots for :-) and put them in a 40L that was 1/2 full of water
and illuminated by a shoplite with a relatively new vitalite and an agro
light. In addition, the ubiquitous (in my room anyway) hygro corymbosa
(is that what hygro stricta or nymphalia(?) stricta is called these days?)
are in the tank, as well as Crypt. wendtii.

I pretty much ignored the tank for the past month - there's no fish in it,
it wasn't evaporating too rapidly, and I kept planning to make room
in a 'real' sort of display tank that I was going to set up somewhere...

Anyway, I did make one or two water changes in the tank, the last about 10 days
ago and noticed long runners along the water's surface from the non-bleheri
echinodorus! None of the swords had lost many leaves, if any (though all
leaves were submerged, some were near the surface.) Isn't that how these
plants reproduce? My previous experiences with echinodorus have been total
aquatic meltdown, much like people claim to see with crypts (but I haven't
for the few varieties I keep.) How do you culture the offshoots? snip them
off and pot them up?:

Oh, the potting mix was real sophisticated- a crushed lump of Aquarium
products laterite from some bags I bought about 5 years ago (hey, can compressed
dirt/clay go bad?) and gravel from a tank of large (10" and 8") cichlids that
hasn't been vacuumed in recent memory. From the plants perspective, I think
I could almost hear them saying "Yum! Cichlid poop! Our favorite!"

This has, however, precluded me from whining about how difficult Echinodorus
are to grow. Further, my 'theory' that you must use incandescent light
(I even bought a couple 'dome' style clip-on lights for the 40L, but I don't
need them now) is dashed as well.

There's no visible algae since I refuse to use trace elements or whatnot,
but I think I'm planning to put some guppies in the tank along with
a box filter just because, well, I need the space, guppies are that way.

Oh yeah, my tap water is very hard (KH 8, GH 18 usually) and mildly
alkaline (pH 7.2). It's usually no problem with harder water plants, but
I'd never had *any* success with echinodorus. Hmm...