Would i be able to mix...?

Question

A butterfly peacock bass, a red-tailed catfish, a florid gar, A silver arowana, and a stingray.

Answer 1

That's a load of total bull ANY of those fish will raise your ammonia levels.  First of all, you are asking IF you can group these, which means to me either you have these all in the pond/tank already or you are thinking about it.  Either way, if you added these in, of course it will increase NH3, but your bacteria from your filter will adjust for that in a short time in a mature tank.  Another sign of total lack of intelligence here, is that in order to group this group, you'd need a MASSIVE pond, and even though NH3 is going in, it's also not going to get to an exremely toxic ppm, I'm saying probably won't hit 2.0 ppm due to the sheer mass of the water, before your biological filter kicks in.

In terms of temperment, I don't see why not.  You realize your parents house needs a pond of like 7-8,000 gallons?  This is just simply not going to work in a tank.

Answer 2

I don't think that the stingray will get along with the others. And if the peacock bass is from a lake it'll just raise your ammonia and nitrate levels and will cause poisonning to the other fishes.