You dont have to sell them, put them in the 75g and wait till the severum and poly grows alittle in the 125g then introduce the jag in the 125g once all the small ones get bigger and settled in.I might take what little fish I do have out of one of my 20Ls and put the male jag in it and set up the 75 for it. I bought these guys from Jeff Rapps and they're just such great quality fish and I hate to let them go.