I got a Green Terror a couple of months ago. It grown maybe 1/4"-1/2" How slow do these guys grow? Compared to Datnoids? I have it in a tank with some little Dats. Here's some pictures...
Thats a great GT! Probably a male just based on its coloring. Mine have been slow growers but the best fix I've found is feeding small earthworms and krill. Mix in the basic cichlid pellet and you're good. Lots of protein in the worms so they'll pack it on good. Cut them up if he's nervous at first tho.
What is the temp? Tank size? Water change schedule?
Yes, terrors grow slow. But it shouldn't be that slow. If you want to speed growth (which I personally don't recommend) bump the temp to about 84, have it alone in a large tank with a constant drip filtration, and feed almost continuously.