hmmm lets see here, i had a 4" gt with a 3" jd, 2" blood parrot, and a sveni pike pair male 6" female 4" all growing out in a 55. so long as you start them together as a community you should do fine. the jd will have alot slower growth than the gt, and also wont get as large so try to give it a head start of about an inch or so. if you wanted to go down a diff path i have a breeding pair of red devils that sure could use a good home. 125+ gallons atleast. (male is very tolerant of the female) where in iowa are you at?