need fish expertise advice.!

[spooky]

Before you do ANY of that you need to trot down to PetsMart or Petco and get an API liquid test tube kit and test your water for ammonia, nitrites and nitrates. I've seen that happen many times (to others) when they put new fish in when the nitrates are sky high. Best to keep them under 20 ppm but at least under 40 ppm. The resident fish have gradually gotten used to the less than stellar water conditions but the new fish can't take it.

Thanks!

 

[fish_n_vw]

I think you should do smaller water changes more often like 25 percent a week. In my 110 I do a 25 percent w/c every week and gravel vac every other time. Also petsmart and petco will test your water if you bring them a sample for free. But it is nice to have your own test kit so you can test it yourself.

 

[EmilyMarie85]

Something else to consider is water temp/salt content/pph... it sounds like the new fish are dying within a few hours of being introduced into your tank... If it was something like ammonia, nitrates or nitrites I would think that the fish already in your tank would be sick as well and from what you are telling us, they are fine, its just the "newbies". That leads me to believe it has something to do with the way you are introducing them to your tank. Are you acclimating them at all??