At the request of Tamlin I am starting this topic and I agree that it should be very productive.
So, Cole asked how we all grow our Utrics and Swords wanted to know about lithotrophic cultivation. Might as well start from the begining I guess.
The majority of my Utrics are grown in 2" square pots that I keep in a seedling flats (i.e. 10x20 trays) that are domed. I fill the trays with water until the level is about to spill over and then I let the level drop until the water is gone, this whole cycle takes about a month or so. My main media is about a 50:50 peat:sand mix but I add 10-20% milled sphag. Sometimes the sphag grows and sometimes it doesn't. There are a few plants that I have found grow better in pure LFS, these being my calycifida, tricolor, longifolia and humboldtii and I am also experimenting with sandersonii (after seeing Tamlin's) and pubescens. In the past I have grown dichotoma in milled sphag. In the summer my plants are outside behind a shade cloth (~40-50% sun) in winter they are under lights.
Variations I have tried and their results:
Pure peat-- I didn't like this, most of my plants grew very slowly and looked almost stunted. I also found it to be prone to algae mats.
LFS over lava rock-- I grew a large colony of calyfifida in this manner. The lava rock layer was only about 2cm deep and it was under 3" or so of LFS but the plants seemed to enjoy it.
My epiphytes are a bit more demanding. My pots of choice are 3" mesh waterlily pots. These provide lots of drainage and ventilation. Medias have been a hayday for me but I have finally settled on 2:1:1:1 LFS:perlite:orchid bark:charcoal. I have used everything from clay pellets to peat to sand mixed in and have found that it is all generally a pain. Watering for these guy started as a pain but I think that was just cause they are a bit picky while establishing. I decided to error on the side of caution and leave they drier to avoid rotting. Now that they are established I have them in a set up similar to my terrestrials except there is a cool breeze always blowing through the dome and the pots stand on styrofoam blocks. When I water it is only to the point where the level just covers the foam with a film, then I let the tray dry as above.
Sword's lithotrophy idea intrigues me and I think I will set up a couple pot this week to test it. I will attempt it with calycifida, sandersonii and livida and then progress from there. My planned mix will be 2:1 lava rock:milled sphag. I also recall one of Slack's books mentioning a media of 1:1 orchid bark:LFS for calycifida.
So, who's next