Fish Dieing

[Poppie]

I joined this site to help my wife. She is going crazy. Her fish keep dying...She follows all the guide lines. Test the water(today the water tested fine nothing wrong),ask for help from the different stores where she buys the fish(Petco,PetSmart,etc.),change to different fish and they keep dieing. Now she thinks because the tank is hexagon, is the reason the fish die. Honestly she is doing all the right things from what I can see. Now what? She is ready to sell the tank and quit. We had fish tanks for years and no problems like this. We are now living in NJ and are retired. Does she need to throw in the towel or can this site help with the problem of our fish dying?? 

 

[Ninjouzata]

What size is the tank and what fish has she had in it? Were they showing any symptoms before they died? What are you using to test the water? Did she cycle the tank?
 
There's likely some questions I've missed but we'll need more info to help you. Hopefully someone can figure it out. I don't think she should give up.

 

[Freedom]

A photo may also be useful for us, along with all the info Nin stated.

 

[sawickib]

On top of what ninj said we may need exact water stats, of your tank, and normal water you use to do water changes.

Tbh petco and petsmart are terrible places for advice and just want your money, they have given me terrible advice in the past and this forum has educated me far more than I could of imagined.