As has been mentioned stay clear of silversides, in the past they were used often but experience and knowledge has moved on. You really don’t need to worry too much about getting your nem fed by the way, it looks a good colour with healthy tentacles already.
If you want to feed the nem, then presumably you feed your fish Mysis? Once you have put some in the tank for the fish use a turkey baster and with the pumps off, lightly squirt a little just above the nem and let it fall down. It will grab hold of the pieces and draw it in. I have 5 rbta’s in my tank and I rarely feed them, maybe once every couple of weeks if that. I chop up a defrosted prawn/shrimp into about quarter inch sizes and drop one onto each nem. The only trouble here is that as you have found, other livestock (in my case, my cleaner shrimp) will try and take the food. This is bad as you really don’t want food ripped out of a nems mouth as it is half devoured. The good thing about mysis or small pieces is you only have to hang around for a minute or 2 until it disappears.
Finally don’t panic about getting your clown hosted, clowns do not need nems and vice versa and there isn’t much you can do apart from let nature take its course. The clown will find it eventually, took mine almost 12 months...
Good luck,
Shaun.
