Platies dying

[Starka]

I have a 26gal tank, i've had it for 6 months and it has been cycled. The temp stays around 76-78. Currently I have two bushynosed plecos, and four platies. Three of the platies I got about three weeks ago and they are doing fine. I had just bought three more platies just a few days ago, but two of them just died this morning. I did notice that they hang out at the bottom before they just died also the tend to open and close their mouths as if breathing hard? I change about 15% every week, my water is good. Ph-7.6, ammonia-0, nitrite-0, nitrate- 0-5, so says my liquid test. When I went back to the store they tested my water but couldn't figure why they died. So I have no idea what is happening to them. Every two weeks I place aquarium salt in the tank. Please help.

 

[Fishie]

Maybe they are starving or someone put something in there that's how my fav. Fish jocktapus died

 

[Mumma.of.two]

Could just be bad stock. Happens sometimes with the stress of the move from the supplier to the LFS, from the LFS to your tank.
How much salt do you add? If the new fish weren't properly acclimatized to your tank/salt level it could have contributed.

 

[Starka]

Well, the third one died this morning. The rest of my platies are doing fine. They don't have the synmtoms as the other ones. I put plenty of food in and suck up what the plecos don't eat, so I don't think that was the problem. The aquarium salt calls for a tablespoon per ten gal. I only put in one instead of two. I guess they just needed to go. Now I've learned my lesson and I should just be patient and wait for my 15gal to cycle before I get any new fish Thanks all for your help.

 

[LyndaB]

How did you acclimate them to your tank?

 

[Starka]

I put the bag in the tank to float for 20mins or so. Then for the next 10min I put little amounts of the tank water in the bag. After that I take them out, throw their water away, dunk them in freshwater, and let them loose in the tank.
I've done that with all my fish, these platies are the first ones to die on me

 

[LyndaB]

What do you mean you "dunk them in freshwater"?

 

[Starka]

It's water that I would normally put in the tank when I clean it out. Its supposed to clean the fish since it came from a store tank and I was putting it with other fish that were currently in the tank. Once I get my 15gal up and cycled I will use that as a quarintine tank so I won't have to do that anymore.