Woes of marine life

So since my sweet child decided she needed a saltwater fish for Christmas, our journey into the marine life world has been rather interesting. Nemo #1 died 3 days after we got him. His sneaky replacement (OH! Nemo must be hiding, Caroline! I'm sure he'll come out soon. #robertdrivesquicklytothefishstore#) lasted a whole 4 weeks. I am currently sitting in my recliner, watching a crab very quickly pick and eat away at the pitiful lifeless body of Dory. Yes, Nemo and Marlin's friend, Dory. We had a whole freakin' movie in our tank just a short time ago. Caroline is sleeping on the couch at the moment, and if she wakes up and sees Dory being eaten, I might just have a meltdown on my hands. Robert has to get home in the next 30 minutes to remedy this situation. I don't touch fish, and I sure as hell don't touch dead, half-eaten fish - that's his department. I'll feed them, add water and chemicals, etc. But I do not touch them. Period. So we now have 2 fish remaining in our little aquatic wonderland. The previous tenants who have gone one to a better place, were quite costly. Have you ever flushed $20 bills down the toilet? Not fun. Yet the fish that remain, were less than $10 each. Go figure. And one, whose name is Skits, is literally crazy - hence his name. He could seriously use some therapy. But it's neat that fish have personalities. It's been fun to watch and see how different they act. But I'm really frustrated at our current tank community. For a while I thought we just weren't very good at this, but the lengthy lifespan of the other fish in the tank dispel that theory. Our tank is obviously balanced as far as chemical levels, etc. So I can't figure out why the fish she wanted are the ones that aren't making it. But that's Robert's department. I just feed, add water, and watch. So I hope we can figure out how to keep her fishy friends alive, because we're only going one more round. I can only flush so many $20 before I start to throw up. So keep your fingers crossed that we can figure this out before my patience, and wallet, wears too thin. :-)