Anguilla bicolor tankmates?

[Randomguyman820]

i have 4 25-ishcm anguilla bicolor shortfin eels, they are warm water fish, currently in a temp tub cause im moving them to a 1000l pond for 2-ish years, and i was wondering what tank/pondmates can i get them? when they reach max size, im going to put them in a pond thats roughly under 5000 gallons or around 18000l