Mass Zebra Danio Genocide :(

[DropkickDragout]

Thanks for the help, I'll do exactly that

 

[killudead]

as i read this entire thread, no one has mentioned the simple fact of did you acclimate the fish before putting them in the tank.
Fish are known to die if they are stressed. As for petco, usually you have 7 days to return the dead fish and they will give you a new one. You bought many glofish, so they were not cheap. Perhaps being new to the world of aquatics, you should have started with something cheaper and worked up to the somewhat expensive fish. Just leave the fish in there and do the water changes as mentioned.
By you messing with the tank so much you are only stressing the fish even more. Perhaps leaving the light off after will help in relieving some stress.

 

[KittyKat]

as i read this entire thread, no one has mentioned the simple fact of did you acclimate the fish before putting them in the tank.
Fish are known to die if they are stressed. As for petco, usually you have 7 days to return the dead fish and they will give you a new one. You bought many glofish, so they were not cheap. Perhaps being new to the world of aquatics, you should have started with something cheaper and worked up to the somewhat expensive fish. Just leave the fish in there and do the water changes as mentioned.
By you messing with the tank so much you are only stressing the fish even more. Perhaps leaving the light off after will help in relieving some stress.

Reading between the lines of the first post, it looked as if the fish had been there for a while before they started dying. If that is not the case, then you might be right.. although danios are generally quite hardy and not as affected by stress as many other fish.

 

[DropkickDragout]

Good news, the 7th Danio is up and swimming with the other three now. and yes, the fish were properly acclimated, I let them float in their bag for quite a while and did partial water transfers into the beg to help them get used to the new water chemistry. Also, yes the fish were in for about 10 days before they started dying.

 

[OldMan47]

Keep an eye on your nitrites using a proper liquid type test kit and just change enough water to always have nitrites less than 0.25 ppm. It should be the only thing you need to test for in the next few weeks, until nitrites drop to zero and stay there on their own. At that point nitrates will become a bit more important to you as they will tell you how often and how much water to change to keep your tank chemistry stable. If you don't end up with a nitrate kit, just change about 30% of the water weekly and that should take care of the average stocking level.