Just tossing out some of the nems I am thinking of adding. I have a few in my home tank that aren't being appreciated; some due to bad placement, some due to a lack of time on my part.
Red mini carpet. This guy recently split into 3, so one is headed to my work tank. They max out at about 2 inches, so he'll fit right in.
Red beadlet anemone. Although typically these are not tropical, this one has been with me for 3+ years in my tropical reef tank. It is non-photosyntetic, but has done well with minimal feedings, so a weekly mysis or two should be enough to get him by.
Green rock anemone. Formerly a good solid green, he was displaced by GSP, and I assumed dead. Recently he resurfaced white as a ghost and smaller than a palythoa. Since then, I have been feeding him and have relocated him to the sump so I don't lose him again. His color is improving, and he has doubled in size.
Green BTA. This one had to be removed from my display and placed in the sump. It has been sadly mistreated and deserves a better life, so it is going to work with me, where it will receive good light, flow, and food.
Blue maxi mini. This one came from my 1.5g cube, and is currently in my sump also. He, as well as some of the corals shown, will be coming back to work also.
All of these anemones can easily be taken home again if they don't fare well, but hopefully, they will thrive in my pico.