And I don't remember for certain whether you ever tried to grow Ruppia...did you say that you didn't want to keep trying any silty/dirty substrate (which Ruppia needs -- grown in pure sand it needs fertilizer added to the water) because something about that kind of system invariably kills off the shrimp? Sorry it was a very long time ago and I can't find that thread. Maybe it wasn't even on this forum. Maybe it wasn't even you.
Rubraita, that looks very nice. Where did you collect the Ruppia? Last week I visited an estuary in New England where it is the dominant plant but it was nowhere to be seen. In August it abruptly disappears. Some individuals produce seeds and then die entirely; some individuals live from year to year in the form of rhizomes under the silt. I wanted to look in the muck for those rhizomes but due to physical disability I couldn't safely do that. I am feeling very disappointed.
I wonder if the Ruppia is entirely safe for the shrimp over the long term. How often do you change the water? Must you remove dead material frequently? Does the Ruppia display a seasonal die-off or does it grow continually in your tank? How many hours of light per day do you provide?