Fishtank/Fish/Equipment/Petsto... Problems. Help!?

Firstly, I suspect your tank wasn't cycled when you added the fish. It's a long process, you can read about it here: http://www.fishkeeping.co.uk/articles_51/fishless-cycling-article.htm You can cycle your tank with fish, but it's not recommended. Secondly, if you add all the fish at once, it'll cause an ammonia spike, and it will affect your fish. Thirdly, you are badly stocked. Petstores sell baby fish, you cannot judge what you can fit in your tank based on how the stores stock their tanks. They can have a dozen of small Blue Gouramis without problem, just because they are babies and store tanks have incredible flirtation. (Male gouramis once they grow up, have territories they protect from others to their death.) The best solution is to read up on the needs of fish, before buying them. E.g. a molly grows up to 9-10 cms, so it cannot be kept in a 10g. Stocking a 10g can be very tricky because of its small size (here are some stocking ideas: http://answers.yahoo.com/question/index;_ylt=Av8X3XGgB57mvIJKX11JPBbty6IX;_ylv=3?qid=20120327215047AAsJDTr) Fourthly, selecting a fish. You have to be very picky and you have to know the most common diseases so that you can avoid picking a sick fish. Goldfish are a no-no for 10g tanks, but this site has a good description on what to look for when buying a fish: http://www.kokosgoldfish.com/tensteps.html

Firstly, I suspect your tank wasn't cycled when you added the fish. It's a long process, you can read about it here: http://www.fishkeeping.co.uk/articles_51/fishless-cycling-article.htm You can cycle your tank with fish, but it's not recommended. Secondly, if you add all the fish at once, it'll cause an ammonia spike, and it will affect your fish. Thirdly, you are badly stocked. Petstores sell baby fish, you cannot judge what you can fit in your tank based on how the stores stock their tanks. They can have a dozen of small Blue Gouramis without problem, just because they are babies and store tanks have incredible flirtation. (Male gouramis once they grow up, have territories they protect from others to their death.) The best solution is to read up on the needs of fish, before buying them. E.g. a molly grows up to 9-10 cms, so it cannot be kept in a 10g. Stocking a 10g can be very tricky because of its small size (here are some stocking ideas: http://answers.yahoo.com/question/index;_ylt=Av8X3XGgB57mvIJKX11JPBbty6IX;_ylv=3?qid=20120327215047AAsJDTr) Fourthly, selecting a fish. You have to be very picky and you have to know the most common diseases so that you can avoid picking a sick fish. Goldfish are a no-no for 10g tanks, but this site has a good description on what to look for when buying a fish: http://www.kokosgoldfish.com/tensteps.html

Three weeks is not enough to do a nitrogen cycle to your aquarium You need to make sure you understand what a nitrogen cycle is, and how to do it. For details http://petskeepersguide.com/fishless-cycle-nitrogen-cycle/ http://petskeepersguide.com/reasons-behind-why-average-fish-only-live-for-3-weeks-after-sold/

I have slight dyslexia with certain words and phrases, so if I misread something and repeat something you did right, just ignore it. Not trying to be condescending. ;) Sometimes, it comes off as rude here. lol But, how did you acclimate them? It's possible the water in your tank was much different than what they were in. Did you cycle the tank first? Nitrogen cycle? Also, PetSmart is a legit place to buy fish, however, I did buy a couple of Bettas that had Ich and because of the horrible water they were in, I didn't recognize it until I got home. So, it is possible to get bad fish from anywhere. Did you test the water yourself or have PetSmart test it? Sometimes their tests are inaccurate. I just had mine tested today by two of my own tests, different brands, and PetSmart and PetSmart's test were drastically different than my own tests with regards to ammonia and alkalinity. It's possible the tests are inaccurate. If you tested it yourself, what brand did you use? I'm reading and re-reading your post and can't seem to find anything else that might have been wrong, except acclimation or just weak/sick fish to begin with.... If you take your fish to PetSmart, they are usually pretty helpful in figuring out why they died, or if anything was wrong. I'd call them to double check first, though. Because one PetSmart near me is SUPER friendly and intelligent, but another one acts as if I'm wasting their time when I ask a simple question. I really can't think of anything else it could be, besides cycling, bad tests, weak/sick fish, and method of acclimation.

I have slight dyslexia with certain words and phrases, so if I misread something and repeat something you did right, just ignore it. Not trying to be condescending. ;) Sometimes, it comes off as rude here. lol But, how did you acclimate them? It's possible the water in your tank was much different than what they were in. Did you cycle the tank first? Nitrogen cycle? Also, PetSmart is a legit place to buy fish, however, I did buy a couple of Bettas that had Ich and because of the horrible water they were in, I didn't recognize it until I got home. So, it is possible to get bad fish from anywhere. Did you test the water yourself or have PetSmart test it? Sometimes their tests are inaccurate. I just had mine tested today by two of my own tests, different brands, and PetSmart and PetSmart's test were drastically different than my own tests with regards to ammonia and alkalinity. It's possible the tests are inaccurate. If you tested it yourself, what brand did you use? I'm reading and re-reading your post and can't seem to find anything else that might have been wrong, except acclimation or just weak/sick fish to begin with.... If you take your fish to PetSmart, they are usually pretty helpful in figuring out why they died, or if anything was wrong. I'd call them to double check first, though. Because one PetSmart near me is SUPER friendly and intelligent, but another one acts as if I'm wasting their time when I ask a simple question. I really can't think of anything else it could be, besides cycling, bad tests, weak/sick fish, and method of acclimation.