Aaquarium newbie needs help?

[Jose]

I decided to try fish as a pet so i bought an aquarium an the pet store person told me a Lil about setup & cycling w/ a couple of cheap fish. A month later i did sum cleaning an a black sponge in the filter had started turning brown. I replaced the blue filter but the aquarium i got only came with 1 black sponge. Since it was brown & slimy i washed it with dawn cuzd on t v they show them cleaning oiled animals wit so i thought it was. Safe.i accidently left sum soap on it an an hour later the top of the water was super bubbly like abubble bath an all my fish wer dead. I'm too embarased to go back to the per store. Any tips or advice for my second. Try