Mass tank die off

[jami m]

we have a 7.5 gallon planted tank with 3 neon tetras, a golden mystery snail, and two ADFs (and one very small uninvited bladder or pond snail) and I cleaned the tank three days ago with a roughly 20% water change (I replaced around 1.5-1.75 gallons of water). A short few hours later all the neon tetras were dead as well as the bladder/pond snail. in addition to the deaths, the mystery closed up in his shell for a couple days and just opened back up to roam around. I did't do anything different about cleaning the tank and all the tests (chlorine, nitrate, nitrite pH) were perfectly fine at the time of cleaning as well as when all the fish died, the water was very cloudy and has cleared up since, but i presume that was just bacterial bloom. The next day we took a water sample to the local petstore to have them check it out and they said everything looked fine and they have no idea why everything would have died so suddenly. The pet store people suggested we use a product called stress zyme to help with the bacterial bloom and to keep the tank healthy, so we came home and added that.I just went to check on the tank and it seems that one of the frogs may have died as he was leaning against one plant backwards. What is happening with my tank and how do i fix it?

 

[Ron Reefman]

Is this a freshwater tank?
You may not find much help here if it is as this is mostly a saltwater and reef forum.

Good luck and sorry to hear about your issues.

 

[GeoSquid]

Did you de chlorinate the the water you used for a water change before adding it to the tank?

 

[Wolf89]

Hey there. For the best responses, I think you should post to FishLore. Thats where'll you get the best information from the people who know the most about freshwater.