Wow are your Angels getting along with the Yellow Lab? I thought it was inadvisable to be mixing the SA cichlids with Africans due to different pH's and temperaments? And, I'm not quite sure about those Penguin Tetra too... I would think the Lab would bully them?
They get along just fine. Haven't had an issue with the penguins, I'm more concerned about the 2 tiny little rummynose tetras I put in there with the penguins but they're doing great and the lab pays no attention at all to them.
I run angel parameters in the tank. The lab just has to deal with it. Low PH and soft water isn't going to kill him.
It is inadvisable I'll give you that and I don't advise it either unless your willing to risk your fish lol. I've done this with three separate tanks and have never had a problem. The angels are actually fairly aggressive fish but do not display that aggression unless breeding or provoked. If breeding they WILL off the yellow lab fairly easily. First time I did this (2 angels and one yellow lab) the angels were the boss and mr. yellow always steered clear of them. Why they were the boss will be clear after I explain round three.
Round two was the same.
Chapter 3: Fish Are Not as Dumb as They Seem
Now this does not work with all fish. Some are smarter than others and some have an easier temperament to break. My experience with labs is they are easy to condition. The fact that he is alone in there plays a big role as well.
The knowledge in layman's terms: Yellow lab mean = lab harassing other fish.
The problem: Potentially stressed out and/or dead fish. No fun for anyone in there.
The solution: Got him as a juvenile and The wrath of god
I created his environment, I change it, remove things, mold it to my liking, I introduce life, I remove life.... in short, to him, I am god lol. Every time I see him chase any other fish around I'll stick my arm in the tank and chase him around a bit. If I can catch him with my bare hand I do. If he tries to hide in his cave I flip it upside down for a while. With him I've had to do this approximately 20 times, now he doesn't chase anyone anymore.
Hes a food hog as well, darts around, scoops everything up and doesn't give the others a chance. All I do now is stick my finger in the tank and he stays away, giving the others who don't fear my almighty finger to gather around it and have a feast lol.
I've broken him. Now instinctual traits can always come back but so long as he remains the only cichlid in there I should be ok.