well, I feel the need to say a few words in regards to the petco situation.
I started my first tank (80g) in 10/05. since I knew nothing, and I hadn't heard of any internet reef sites, my lfs guy sold me and put this tank together. He was supposed to be the knowledgeable one, well he was the one who told me I could add fish a week after getting the thing set up. I went to my local petco (his competitor of course) and bought a foxface, 6 damsels, & a clown fish. well, to this day, all the petco animals surivived the "cycling" period that the lfs didn't inform me that I would have. not only did they survive, they are all alive to this day--3 years later. this particular lfs couldn't keep a fish alive if his life depended on it. this lfs is now out of business.
I went back to petco last week. I have since done a 180g upgrade that has 3 fish. I wanted more. so, petco had 2 black ocelaris clowns and a pretty tang. a full week later they are all three doing great!! went back two days ago, and wanted a foxface due to a HA outbreak in my frag tank. I found the so-called "aquatic specialist" and he mentioned how they were considered "deathco". I told him of this site, and said "I would be scared b/c petco gets bashed so much". I said "you are right". According to him, headquarters gives them a budget of $100/week. yes, $100/week to buy any salt water critters. He said he has since gotten them to raise it to $400/week as $100 could not buy anything.
IMO, petco is just like any other LFS. they get a bad rap b/c they are a chain. but, IMO if your particular store mgr doesn't give two licks, then you will have a store that sells cruddy animals. Obviously, my petco has hired a young lad who admitted to me he knows nothing about reefs (this store doesn't sells corals anyway besides condylactic anemones) but he knew his fishes. He knew how to do water changes, he new how to care for the fish, he put the tangs in the biggest tanks they had, and the snails in the small tanks.
a store is only as good as the personnel it hires. in my case, the petco was much cleaner, & nicer than the LFS that was 1 mile down the road. Petco's are not any different than any LFS-you got some good ones you got some bad ones (unfortunately).