I want to do 1 cichlid in a 75g(most likely green terror) with some wider-bodied tetras...I'm thinking a school of serpae, lemon, or diamond tetras. I wouldn't mind going with some swordtails either. Is this possible?
I have used similar fish for dithers with my mid-sized cichlids with mixed results. The problem I have found with the tetras is that they aren't the fastest swimmers, so they slowly get picked off one by one over time. I tend to heavily stock my tanks, so that has a lot to do with it. You may have good luck with the GT and a school of tetras until the GT gets big enough to eat them.
My 6" ebjd is fine with swordtails and mollies. Bought a dozen lemon tetras and was down to 5 in less than a weeks time. He and my 5" Nic do a nice job of keeping the mollie and swordtail population in check.
As long as it won't fit in his mouth they should be fine.
I notice my GT picking off the tetra while they slept.
Even my Angels knew how to pick off silver tips & rummy noses.
Give them ample hiding spots & you'll better their chances.