set up of a freshwater tank

Question
My mother wanted to get freshwater fish today and I took her out and got her a 10 gallon tank, gravel, filter a substrate for the fish, and a few fake plants for decor, i also bought her water conditioner for the water since she wanted to use tap water. i took her back to her home and cleaned her tank to get it ready put the rocks and decor in it and let it filter through with the water and conditioner for a while then she added her fish after letting them sit in the bags for about 20 minutes. she got a kissing fish, 2 angel fish, 4 small neons and some type of bigger blue fish and a pacostamus (sp)?. the fish seem to be okay after a bit i went in to check on them and 2 of the neons had died and the blue fish had started attacking the 3rd neon in the face and killed it. so i removed the blue fish into a fish bowl on its own in case it was the reason the neons had died. i am just curious as to if i should have done anything else or did i do anything wrong in the tank set up as far as adding anything else to the water or putting the fish in to soon. any help you can offer would be great i have never set up a fish tank of any kind before and my mother is to old to remember how to since its been a while since she has had one of her own. thank you and all help appreciated.

tia from Tallahassee, fl.

Answer
I will need a little more information from you in order to try to figure out what is going on. You are saying "blue fish". Do you know what type of fish it is?  This will make a big difference in letting you know about the fish. Researching these things PRIOR to buying is WELL WORTH the time.

In the meantime, please research the proper way to "cycle" your tank. This NEEDS to be done in order for any fish to survive and thrive in a tank, especially with more delicate fish such as the ones you have.  You also need to research fish compatibility, meaning which fish do well together, as not all fish "get along" well enough to be in the same tank.

At this time, I believe your mother would be best suited by having "hardy" fish that can withstand someone learning the ins and outs of fishkeeping. This would be fish such as Danios, Platys, Guppies, etc.  She can move on to "bigger and better" as you both learn about keeping the fish the correct way.

Here are a couple of links to check out:

http://www.firsttankguide.net/sitemap.php
http://fins.actwin.com/mirror/fish-popular.html#first
http://www.fishlore.com/GoodFirstFish.htm

Obviously, if the blue fish is trying to beat up/kill the others, you need to remove him from the tank. I may be able to offer suggestions if you let me know what type in a follow-up to this.

I will wait to hear from you.