i have a sizable SD in a 30 gal tank and wish to put him in my larger tank. the only downside would be that my oscar is 9" my pacu is 12" my plecs are 7" and 13+" and a syno cat about 6-7". my silver dollar is 2-2.5"L and a little less then 2" tall. how long should i wait before putting the SD with the oscar and his friends?