There are plenty of poisonous stuff around that affects one and not the other. What's your point? People come here to get advice. What they do with it is up to them. I was told you can't put 3 dwarf angels in a tank together. Yet, I did and all get along fine. Yes, I did research the angels and there were mixed opinions. I took what I thought were the best for my situation and it worked. I'm done with this topic now.