I'm interested to hear how you plan to add more ATF to a larger one. If you're successful in manipulating growth on some and limiting growth on another it would be a very interesting process. I've been thinking of replacing my three VATFs that I lost but I don't think I could grow out more fast enough to match the bigger ones.
While I feel that my plan is sound in theory, I am having a good bit of trouble actually implementing it.
The trouble I'm running into is primarily a lack of fish. I have a fatf and I have a line on a batf, but I've not had any luck in finding any vatf or tatf
that are for sale. Max doesn't bother fish that are significantly smaller than him, he lives with a 6-7" red tail black shark that he completely ignores. At one point driven by pure curiosity, I dropped the 5.5" fatf into the main tank just to see what would happen. Max ignored him. The main problems were my juruense who I have no doubt would have eaten it if given a chance and Drogo, my black aro, who was actively hunting the fatf but was far to slow to catch it.
I strongly suspect that once the tigers are large enough to survive Drogo's interest, they will be able to get along ok. After all, as you've been experiencing, it appears that gatf aren't normally the problem in mixed ATF communities. Several members, you and DayumDanny come to mind immediately, had trouble with vatf attacking tankmates.
If I can get passed this headache inducing step of getting all five specimens while Max is still borderline small enough to play nice with others, if I can't get all five soon, I feel this initiative will fail unless I sell Max (which won't happen).
I'll be sure to continue posting updates as they become relevant.