My Black Nasty is the slowest growing fish I have ever owned. I got it at the same time (6 mon) and size (1") as my Trimac and there is at least a 5" difference now. The Black Nasty has grown 1" in 6 months. I bought little tiny 1/4" Convicts as dithers a month ago and the Convicts have almost caught up with the Black Nasty in size. Problem I have is my B.N. doesn't allow any other fish in the tank except for these little Cons, seems like a waiste of a 75 gallon having 1 (3") B.N. and 3 (2") Convicts.
I do 20% water changes every other day on all my tanks, and I think that's a contributing factor to how fast fish will grown, the more water changes, the faster they grow.
I bought some 1" Amphilophus amarillo two months ago at the GCCA swap, they are now 3", with no special feeding regimen.
I am preparing to buy two in a couple of week's. We hope a matting pair the LFS owner and myself he's pretty cool. He has four and he said that he thinks there pairing up so we will see! But those are some pretty nice fish you got there.
Had mine separated by a divider in a 80'F tank, put them together in a 150 gal did 2 water changes in 24 hours and kept the new tank temp between 84 and 86, within 48 hours of being dropped in that tank they were spawning.
algae's getting thick on the glass because they attack my hand or the magloat when I try to clean it.