couple questions bout em, would they do alright in a 20? would the be compatible with: 1 paradise fish,1 swordtail,and 3 yoyo loaches(been warned they could be aggressive,if they try anything they go to the 55 where they wont pick on anyone a second time). someone sugested these for my 20,and i read they could be skittish. thats alright,because i want a schooling fish that you know,SCHOOLS