I'd had fish as a little kid, and all of a sudden one day I suddenly had the urge to get back into keeping fish(I really didn't do much the 1st time around, aside from feeding them. My father did most of the work...And I know know he didn't do it very well). Anyway with my next paycheck I went into the LFS and looked around for a tank that was in my price range. I settled on a 25 gallon tank. I asked the salesman if it was ok to buy fish that day for the tank and he told me no, and that I should go home and fill up the tank and let it sit for a few days. So I filled up the tank, and added all the chemicals I had been told to buy to cycle the tank(I had no idea what "Cycling the tank" meant, so I just listened to the guy. Turns out the "Cycle" stuff is useless). Anyway I came back about 5 days later and purchased 3 angelfish, 3 redeye tetras and 1 other fish which I have no idea what it was. Needless to say, a few days later 1 of my angelfish kicked the bucket. The LFS I shop at has a 1 week guarentee on all their fish, so I took the dead angel back and got another one. The next day the new angel, and one of the other angels were dead. So I took them both back(At this point it had been over a week since i'd bought the original batch,, so I couldn't get 1 of them replaced for free). I was told to buy a pH testing kit to test my pH, and was given another free angelfish. I got home and tested my pH and it was very high. I called in and told them this and they told me they sell a pH reducer, so I drove in and bought some. After a few days later the pH hadn't dropped at all. I called in again to ask if they had anything stronger for lowering the pH and they said they didn't(During the time the new angel fish had also died, along with the unidentified fish). Anyway I did an online search for other ways to lower your pH and I stumbled across a fish keeping forum(Not this one though). I registered on there and posted my story and asked them what I could do about it, and they informed me of the horrible advice I had been getting from my LFS, and that the deaths were due to the fact that my tank was in the process of cycling, and not because of the pH. I was told to buy Ammonia, Nitrite and Nitrate testing kits to check the status of my water, which I did. I quickly discovered that the ammonia levels were extremely high. I ended up doing water changes virtually every 2nd day for about 2 weeks to get the ammonia down to nothing, and even then I still needed to do 20% water changes every 4 or 5 days for a couple of weeks to make sure it stayed that way.
Needless to say, whenever I have a question nowadays, I come here and ask(I no longer post on the other forum I mentioned. The folks there were great and very informative, but the posting community was much, much smaller and it was sometimes be days before i'd get an answer to my questions.), I don't bother with the LFS employees anymore.